78191665552 has 480 divisors, whose sum is σ = 215150673920. Its totient is φ = 26755660800.

The previous prime is 78191665543. The next prime is 78191665567. The reversal of 78191665552 is 25556619187.

It is a super-2 number, since 2×78191665552² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78191665493 and 78191665502.

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 95 ways as a sum of consecutive naturals, for example, 562529899 + ... + 562530037.

Almost surely, 2^78191665552 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 78191665552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107575336960).

78191665552 is an abundant number, since it is smaller than the sum of its proper divisors (136959008368).

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

78191665552 is a wasteful number, since it uses less digits than its factorization.

78191665552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323 (or 306 counting only the distinct ones).

The product of its digits is 4536000, while the sum is 55.

The spelling of 78191665552 in words is "seventy-eight billion, one hundred ninety-one million, six hundred sixty-five thousand, five hundred fifty-two".