78388800400 has 45 divisors (see below), whose sum is σ = 188342546961. Its totient is φ = 31353280320.

The previous prime is 78388800383. The next prime is 78388800421. The reversal of 78388800400 is 400888387.

The square root of 78388800400 is 279980.

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

It can be written as a sum of positive squares in only one way, i.e., 28219968144 + 50168832256 = 167988^2 + 223984^2 .

It is a super-2 number, since 2×78388800400² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5592601 + ... + 5606599.

Almost surely, 2^78388800400 is an apocalyptic number.

78388800400 is the 279980-th square number.

It is an amenable number.

78388800400 is an abundant number, since it is smaller than the sum of its proper divisors (109953746561).

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

78388800400 is an frugal number, since it uses more digits than its factorization.

78388800400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28016 (or 14006 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 46.

The spelling of 78388800400 in words is "seventy-eight billion, three hundred eighty-eight million, eight hundred thousand, four hundred".