82791440 has 80 divisors (see below), whose sum is σ = 199487232. Its totient is φ = 31936512.

The previous prime is 82791439. The next prime is 82791497. The reversal of 82791440 is 4419728.

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

It is a self number, because there is not a number n which added to its sum of digits gives 82791440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 364607 + ... + 364833.

Almost surely, 2^82791440 is an apocalyptic number.

82791440 is a gapful number since it is divisible by the number (80) 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 82791440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99743616).

82791440 is an abundant number, since it is smaller than the sum of its proper divisors (116695792).

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

82791440 is a wasteful number, since it uses less digits than its factorization.

82791440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 82791440 is about 9098.9801626336. The cubic root of 82791440 is about 435.8413978581.

The spelling of 82791440 in words is "eighty-two million, seven hundred ninety-one thousand, four hundred forty".