78686400 has 252 divisors, whose sum is σ = 282424632. Its totient is φ = 19169280.

The previous prime is 78686369. The next prime is 78686411. The reversal of 78686400 is 468687.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 811152 + ... + 811248.

Almost surely, 2^78686400 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78686400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141212316).

78686400 is an abundant number, since it is smaller than the sum of its proper divisors (203738232).

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

78686400 is a wasteful number, since it uses less digits than its factorization.

78686400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 39.

The square root of 78686400 is about 8870.5354968006. The cubic root of 78686400 is about 428.5155228663.

The spelling of 78686400 in words is "seventy-eight million, six hundred eighty-six thousand, four hundred".