28648767780 has 72 divisors (see below), whose sum is σ = 86954612472. Its totient is φ = 7634981376.

The previous prime is 28648767757. The next prime is 28648767781. The reversal of 28648767780 is 8776784682.

28648767780 is a `hidden beast` number, since 2 + 8 + 6 + 487 + 6 + 77 + 80 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 760435776 + 27888332004 = 27576^2 + 166998^2 .

It is a super-2 number, since 2×28648767780² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28648767781) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 250234 + ... + 346286.

It is an arithmetic number, because the mean of its divisors is an integer number (1207702951).

Almost surely, 2^28648767780 is an apocalyptic number.

28648767780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28648767780 is an abundant number, since it is smaller than the sum of its proper divisors (58305844692).

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

28648767780 is a wasteful number, since it uses less digits than its factorization.

28648767780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97725 (or 97720 counting only the distinct ones).

The product of its (nonzero) digits is 50577408, while the sum is 63.

The spelling of 28648767780 in words is "twenty-eight billion, six hundred forty-eight million, seven hundred sixty-seven thousand, seven hundred eighty".