81332919 has 12 divisors (see below), whose sum is σ = 120656536. Its totient is φ = 52756272.

The previous prime is 81332897. The next prime is 81332929. The reversal of 81332919 is 91923318.

It is not a de Polignac number, because 81332919 - 2⁵ = 81332887 is a prime.

It is a super-2 number, since 2×81332919² = 13230087426121122, 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 (81332929) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 121789 + ... + 122454.

Almost surely, 2^81332919 is an apocalyptic number.

81332919 is a deficient number, since it is larger than the sum of its proper divisors (39323617).

81332919 is a wasteful number, since it uses less digits than its factorization.

81332919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244286 (or 244283 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 81332919 is about 9018.4765343155. The cubic root of 81332919 is about 433.2668414086.

The spelling of 81332919 in words is "eighty-one million, three hundred thirty-two thousand, nine hundred nineteen".