78415646400 has 1680 divisors, whose sum is σ = 363875807680. Its totient is φ = 16124313600.

The previous prime is 78415646389. The next prime is 78415646417. The reversal of 78415646400 is 464651487.

78415646400 is a `hidden beast` number, since 7 + 8 + 41 + 564 + 6 + 40 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1680).

It is a super-2 number, since 2×78415646400² (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 an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 719409546 + ... + 719409654.

Almost surely, 2^78415646400 is an apocalyptic number.

78415646400 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 78415646400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (181937903840).

78415646400 is an abundant number, since it is smaller than the sum of its proper divisors (285460161280).

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

78415646400 is a wasteful number, since it uses less digits than its factorization.

78415646400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The spelling of 78415646400 in words is "seventy-eight billion, four hundred fifteen million, six hundred forty-six thousand, four hundred".