81872881 has 8 divisors (see below), whose sum is σ = 86331200. Its totient is φ = 77429520.

The previous prime is 81872851. The next prime is 81872899. The reversal of 81872881 is 18827818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81872881 - 2⁵ = 81872849 is a prime.

It is a super-2 number, since 2×81872881² = 13406337286480322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81872821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8575 + ... + 15403.

It is an arithmetic number, because the mean of its divisors is an integer number (10791400).

Almost surely, 2^81872881 is an apocalyptic number.

It is an amenable number.

81872881 is a deficient number, since it is larger than the sum of its proper divisors (4458319).

81872881 is a wasteful number, since it uses less digits than its factorization.

81872881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7479.

The product of its digits is 57344, while the sum is 43.

The square root of 81872881 is about 9048.3634431868. The cubic root of 81872881 is about 434.2235340369.

The spelling of 81872881 in words is "eighty-one million, eight hundred seventy-two thousand, eight hundred eighty-one".