81506632 has 8 divisors (see below), whose sum is σ = 152824950. Its totient is φ = 40753312.

The previous prime is 81506627. The next prime is 81506693. The reversal of 81506632 is 23660518.

It can be written as a sum of positive squares in only one way, i.e., 64416676 + 17089956 = 8026^2 + 4134^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 81506594 and 81506603.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5094157 + ... + 5094172.

Almost surely, 2^81506632 is an apocalyptic number.

It is an amenable number.

81506632 is a deficient number, since it is larger than the sum of its proper divisors (71318318).

81506632 is a wasteful number, since it uses less digits than its factorization.

81506632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10188335 (or 10188331 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 81506632 is about 9028.1023476697. The cubic root of 81506632 is about 433.5750829897.

The spelling of 81506632 in words is "eighty-one million, five hundred six thousand, six hundred thirty-two".