81013588 has 12 divisors (see below), whose sum is σ = 146662740. Its totient is φ = 39109952.

The previous prime is 81013573. The next prime is 81013589. The reversal of 81013588 is 88531018.

It can be written as a sum of positive squares in 2 ways, for example, as 14884164 + 66129424 = 3858^2 + 8132^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81013589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 349081 + ... + 349312.

It is an arithmetic number, because the mean of its divisors is an integer number (12221895).

Almost surely, 2^81013588 is an apocalyptic number.

It is an amenable number.

81013588 is a deficient number, since it is larger than the sum of its proper divisors (65649152).

81013588 is a wasteful number, since it uses less digits than its factorization.

81013588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 698426 (or 698424 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 34.

The square root of 81013588 is about 9000.7548572328. The cubic root of 81013588 is about 432.6990639211.

The spelling of 81013588 in words is "eighty-one million, thirteen thousand, five hundred eighty-eight".