78638400 has 252 divisors, whose sum is σ = 288251392. Its totient is φ = 20321280.

The previous prime is 78638387. The next prime is 78638423. The reversal of 78638400 is 483687.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 619137 + ... + 619263.

Almost surely, 2^78638400 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 78638400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144125696).

78638400 is an abundant number, since it is smaller than the sum of its proper divisors (209612992).

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

78638400 is a wasteful number, since it uses less digits than its factorization.

78638400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 78638400 is about 8867.8294976843. The cubic root of 78638400 is about 428.4283713004.

The spelling of 78638400 in words is "seventy-eight million, six hundred thirty-eight thousand, four hundred".