81888597 has 32 divisors (see below), whose sum is σ = 139228160. Its totient is φ = 46597680.

The previous prime is 81888593. The next prime is 81888601. The reversal of 81888597 is 79588818.

It is an interprime number because it is at equal distance from previous prime (81888593) and next prime (81888601).

It is not a de Polignac number, because 81888597 - 2² = 81888593 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81888593) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52722 + ... + 54252.

It is an arithmetic number, because the mean of its divisors is an integer number (4350880).

Almost surely, 2^81888597 is an apocalyptic number.

It is an amenable number.

81888597 is a deficient number, since it is larger than the sum of its proper divisors (57339563).

81888597 is a wasteful number, since it uses less digits than its factorization.

81888597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1830 (or 1824 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 54.

The square root of 81888597 is about 9049.2318458530. The cubic root of 81888597 is about 434.2513162133.

The spelling of 81888597 in words is "eighty-one million, eight hundred eighty-eight thousand, five hundred ninety-seven".