78401728440 has 512 divisors, whose sum is σ = 318742272000. Its totient is φ = 16742412288.

The previous prime is 78401728429. The next prime is 78401728499. The reversal of 78401728440 is 4482710487.

It is a super-2 number, since 2×78401728440² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 10481982 + ... + 10489458.

It is an arithmetic number, because the mean of its divisors is an integer number (622543500).

Almost surely, 2^78401728440 is an apocalyptic number.

78401728440 is a gapful number since it is divisible by the number (70) 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 78401728440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159371136000).

78401728440 is an abundant number, since it is smaller than the sum of its proper divisors (240340543560).

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

78401728440 is a wasteful number, since it uses less digits than its factorization.

78401728440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7596 (or 7586 counting only the distinct ones).

The product of its (nonzero) digits is 401408, while the sum is 45.

The spelling of 78401728440 in words is "seventy-eight billion, four hundred one million, seven hundred twenty-eight thousand, four hundred forty".