81276664 has 32 divisors (see below), whose sum is σ = 181739520. Its totient is φ = 33317856.

The previous prime is 81276659. The next prime is 81276683. The reversal of 81276664 is 46667218.

It is a super-2 number, since 2×81276664² = 13211792221937792, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30264 + ... + 32839.

It is an arithmetic number, because the mean of its divisors is an integer number (5679360).

Almost surely, 2^81276664 is an apocalyptic number.

It is an amenable number.

81276664 is an abundant number, since it is smaller than the sum of its proper divisors (100462856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81276664 is a wasteful number, since it uses less digits than its factorization.

81276664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63139 (or 63135 counting only the distinct ones).

The product of its digits is 96768, while the sum is 40.

The square root of 81276664 is about 9015.3571199371. The cubic root of 81276664 is about 433.1669267696.

The spelling of 81276664 in words is "eighty-one million, two hundred seventy-six thousand, six hundred sixty-four".