81902520 has 144 divisors (see below), whose sum is σ = 309708360. Its totient is φ = 18716544.

The previous prime is 81902507. The next prime is 81902533. The reversal of 81902520 is 2520918.

It is an interprime number because it is at equal distance from previous prime (81902507) and next prime (81902533).

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, 15319 + ... + 19961.

Almost surely, 2^81902520 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 81902520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154854180).

81902520 is an abundant number, since it is smaller than the sum of its proper divisors (227805840).

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

81902520 is a wasteful number, since it uses less digits than its factorization.

81902520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4674 (or 4660 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 81902520 is about 9050.0011049723. The cubic root of 81902520 is about 434.2759258198.

The spelling of 81902520 in words is "eighty-one million, nine hundred two thousand, five hundred twenty".