78615772398 has 64 divisors (see below), whose sum is σ = 181008691200. Its totient is φ = 25265507040.

The previous prime is 78615772381. The next prime is 78615772399. The reversal of 78615772398 is 89327751687.

78615772398 is a `hidden beast` number, since 7 + 8 + 615 + 7 + 7 + 2 + 3 + 9 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78615772399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 363015 + ... + 537597.

It is an arithmetic number, because the mean of its divisors is an integer number (2828260800).

Almost surely, 2^78615772398 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78615772398, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90504345600).

78615772398 is an abundant number, since it is smaller than the sum of its proper divisors (102392918802).

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

78615772398 is a wasteful number, since it uses less digits than its factorization.

78615772398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174894 (or 174888 counting only the distinct ones).

The product of its digits is 35562240, while the sum is 63.

The spelling of 78615772398 in words is "seventy-eight billion, six hundred fifteen million, seven hundred seventy-two thousand, three hundred ninety-eight".