81157955 has 16 divisors (see below), whose sum is σ = 99944064. Its totient is φ = 63237120.

The previous prime is 81157939. The next prime is 81157957. The reversal of 81157955 is 55975118.

It is not a de Polignac number, because 81157955 - 2⁴ = 81157939 is a prime.

It is a super-2 number, since 2×81157955² = 13173227319564050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81157957) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55919 + ... + 57351.

It is an arithmetic number, because the mean of its divisors is an integer number (6246504).

Almost surely, 2^81157955 is an apocalyptic number.

81157955 is a deficient number, since it is larger than the sum of its proper divisors (18786109).

81157955 is a wasteful number, since it uses less digits than its factorization.

81157955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1726.

The product of its digits is 63000, while the sum is 41.

The square root of 81157955 is about 9008.7710038606. The cubic root of 81157955 is about 432.9559360423.

The spelling of 81157955 in words is "eighty-one million, one hundred fifty-seven thousand, nine hundred fifty-five".