81298520 has 16 divisors (see below), whose sum is σ = 182921760. Its totient is φ = 32519392.

The previous prime is 81298507. The next prime is 81298541. The reversal of 81298520 is 2589218.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1016192 + ... + 1016271.

It is an arithmetic number, because the mean of its divisors is an integer number (11432610).

Almost surely, 2^81298520 is an apocalyptic number.

It is an amenable number.

81298520 is an abundant number, since it is smaller than the sum of its proper divisors (101623240).

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

81298520 is a wasteful number, since it uses less digits than its factorization.

81298520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2032474 (or 2032470 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 81298520 is about 9016.5691923259. The cubic root of 81298520 is about 433.2057507378.

It can be divided in two parts, 81298 and 520, that added together give a palindrome (81818).

The spelling of 81298520 in words is "eighty-one million, two hundred ninety-eight thousand, five hundred twenty".