81505024 has 36 divisors (see below), whose sum is σ = 163683520. Its totient is φ = 40504320.

The previous prime is 81505009. The next prime is 81505037. The reversal of 81505024 is 42050518.

It is a self number, because there is not a number n which added to its sum of digits gives 81505024.

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, 45457 + ... + 47215.

Almost surely, 2^81505024 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 81505024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81841760).

81505024 is an abundant number, since it is smaller than the sum of its proper divisors (82178496).

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

81505024 is a wasteful number, since it uses less digits than its factorization.

81505024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1956 (or 1942 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 81505024 is about 9028.0132919707. The cubic root of 81505024 is about 433.5722317153.

The spelling of 81505024 in words is "eighty-one million, five hundred five thousand, twenty-four".