28767779389440 has 3840 divisors, whose sum is σ = 133949591123040. Its totient is φ = 5850299105280.

The previous prime is 28767779389423. The next prime is 28767779389457. The reversal of 28767779389440 is 4498397776782.

28767779389440 is a `hidden beast` number, since 2 + 8 + 7 + 6 + 7 + 7 + 7 + 93 + 89 + 440 = 666.

It is an interprime number because it is at equal distance from previous prime (28767779389423) and next prime (28767779389457).

It is a tau number, because it is divible by the number of its divisors (3840).

It is a Smith number, since the sum of its digits (81) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 28767779389440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 346599751639 + ... + 346599751721.

Almost surely, 2^{28767779389440} is an apocalyptic number.

28767779389440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28767779389440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66974795561520).

28767779389440 is an abundant number, since it is smaller than the sum of its proper divisors (105181811733600).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28767779389440 is an equidigital number, since it uses as much as digits as its factorization.

28767779389440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 7169347584, while the sum is 81.

The spelling of 28767779389440 in words is "twenty-eight trillion, seven hundred sixty-seven billion, seven hundred seventy-nine million, three hundred eighty-nine thousand, four hundred forty".