78640984900 has 81 divisors (see below), whose sum is σ = 176921325399. Its totient is φ = 30340282560.

The previous prime is 78640984843. The next prime is 78640984907. The reversal of 78640984900 is 948904687.

The square root of 78640984900 is 280430.

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 1080962884 + 77560022016 = 32878^2 + 278496^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78640984907) 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, 81324217 + ... + 81325183.

Almost surely, 2^78640984900 is an apocalyptic number.

78640984900 is the 280430-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78640984900

78640984900 is an abundant number, since it is smaller than the sum of its proper divisors (98280340499).

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

78640984900 is an equidigital number, since it uses as much as digits as its factorization.

78640984900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2006 (or 1003 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 55.

The spelling of 78640984900 in words is "seventy-eight billion, six hundred forty million, nine hundred eighty-four thousand, nine hundred".