81597229 has 32 divisors (see below), whose sum is σ = 105062400. Its totient is φ = 61689600.

The previous prime is 81597221. The next prime is 81597233. The reversal of 81597229 is 92279518.

It is not a de Polignac number, because 81597229 - 2³ = 81597221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81597221) 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, 341292 + ... + 341530.

It is an arithmetic number, because the mean of its divisors is an integer number (3283200).

Almost surely, 2^81597229 is an apocalyptic number.

It is an amenable number.

81597229 is a deficient number, since it is larger than the sum of its proper divisors (23465171).

81597229 is a wasteful number, since it uses less digits than its factorization.

81597229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433.

The product of its digits is 90720, while the sum is 43.

The square root of 81597229 is about 9033.1184537788. The cubic root of 81597229 is about 433.7356672921.

The spelling of 81597229 in words is "eighty-one million, five hundred ninety-seven thousand, two hundred twenty-nine".