78837408400 has 135 divisors (see below), whose sum is σ = 192686922363. Its totient is φ = 30998112000.

The previous prime is 78837408389. The next prime is 78837408401. The reversal of 78837408400 is 480473887.

It is a happy number.

The square root of 78837408400 is 280780.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 14556905104 + 64280503296 = 120652^2 + 253536^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78837408401) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 567175531 + ... + 567175669.

Almost surely, 2^78837408400 is an apocalyptic number.

78837408400 is the 280780-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78837408400

78837408400 is an abundant number, since it is smaller than the sum of its proper divisors (113849513963).

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

78837408400 is a wasteful number, since it uses less digits than its factorization.

78837408400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 1204224, while the sum is 49.

Multiplying 78837408400 by its sum of digits (49), we get a square (3863033011600 = 1965460²).

The spelling of 78837408400 in words is "seventy-eight billion, eight hundred thirty-seven million, four hundred eight thousand, four hundred".