78811992 has 144 divisors (see below), whose sum is σ = 252088200. Its totient is φ = 22176000.

The previous prime is 78811987. The next prime is 78812003. The reversal of 78811992 is 29911887.

It is a super-2 number, since 2×78811992² = 12422660166016128, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 313867 + ... + 314117.

Almost surely, 2^78811992 is an apocalyptic number.

78811992 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78811992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126044100).

78811992 is an abundant number, since it is smaller than the sum of its proper divisors (173276208).

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

78811992 is a wasteful number, since it uses less digits than its factorization.

78811992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366 (or 352 counting only the distinct ones).

The product of its digits is 72576, while the sum is 45.

The square root of 78811992 is about 8877.6118410302. The cubic root of 78811992 is about 428.7433873755.

The spelling of 78811992 in words is "seventy-eight million, eight hundred eleven thousand, nine hundred ninety-two".