79631440 has 80 divisors (see below), whose sum is σ = 215664768. Its totient is φ = 26777088.

The previous prime is 79631429. The next prime is 79631441. The reversal of 79631440 is 4413697.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 79631396 and 79631405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79631441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28339 + ... + 31021.

Almost surely, 2^79631440 is an apocalyptic number.

79631440 is a gapful number since it is divisible by the number (70) 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 79631440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107832384).

79631440 is an abundant number, since it is smaller than the sum of its proper divisors (136033328).

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

79631440 is a wasteful number, since it uses less digits than its factorization.

79631440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2756 (or 2750 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 79631440 is about 8923.6449951799. The cubic root of 79631440 is about 430.2242205411.

The spelling of 79631440 in words is "seventy-nine million, six hundred thirty-one thousand, four hundred forty".