81476564 has 12 divisors (see below), whose sum is σ = 153552084. Its totient is φ = 37604544.

The previous prime is 81476539. The next prime is 81476567. The reversal of 81476564 is 46567418.

81476564 is nontrivially palindromic in base 16.

It can be written as a sum of positive squares in 2 ways, for example, as 47720464 + 33756100 = 6908^2 + 5810^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81476567) 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, 783377 + ... + 783480.

It is an arithmetic number, because the mean of its divisors is an integer number (12796007).

Almost surely, 2^81476564 is an apocalyptic number.

It is an amenable number.

81476564 is a deficient number, since it is larger than the sum of its proper divisors (72075520).

81476564 is a wasteful number, since it uses less digits than its factorization.

81476564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566874 (or 1566872 counting only the distinct ones).

The product of its digits is 161280, while the sum is 41.

The square root of 81476564 is about 9026.4369493173. The cubic root of 81476564 is about 433.5217607888.

The spelling of 81476564 in words is "eighty-one million, four hundred seventy-six thousand, five hundred sixty-four".