81733831 has 4 divisors (see below), whose sum is σ = 81855952. Its totient is φ = 81611712.

The previous prime is 81733829. The next prime is 81733843. The reversal of 81733831 is 13833718.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81733831 - 2¹ = 81733829 is a prime.

It is a super-2 number, since 2×81733831² = 13360838259873122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81733811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60051 + ... + 61396.

It is an arithmetic number, because the mean of its divisors is an integer number (20463988).

Almost surely, 2^81733831 is an apocalyptic number.

81733831 is a deficient number, since it is larger than the sum of its proper divisors (122121).

81733831 is a wasteful number, since it uses less digits than its factorization.

81733831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122120.

The product of its digits is 12096, while the sum is 34.

The square root of 81733831 is about 9040.6764680526. The cubic root of 81733831 is about 433.9775714517.

The spelling of 81733831 in words is "eighty-one million, seven hundred thirty-three thousand, eight hundred thirty-one".