81364593 has 32 divisors (see below), whose sum is σ = 121512960. Its totient is φ = 48185280.

The previous prime is 81364589. The next prime is 81364627. The reversal of 81364593 is 39546318.

It is not a de Polignac number, because 81364593 - 2² = 81364589 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81364513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 68898 + ... + 70068.

It is an arithmetic number, because the mean of its divisors is an integer number (3797280).

Almost surely, 2^81364593 is an apocalyptic number.

It is an amenable number.

81364593 is a deficient number, since it is larger than the sum of its proper divisors (40148367).

81364593 is a wasteful number, since it uses less digits than its factorization.

81364593 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269.

The product of its digits is 77760, while the sum is 39.

The square root of 81364593 is about 9020.2324249434. The cubic root of 81364593 is about 433.3230774036.

The spelling of 81364593 in words is "eighty-one million, three hundred sixty-four thousand, five hundred ninety-three".