81590634 has 12 divisors (see below), whose sum is σ = 176779746. Its totient is φ = 27196872.

The previous prime is 81590629. The next prime is 81590653. The reversal of 81590634 is 43609518.

81590634 is a `hidden beast` number, since 8 + 1 + 590 + 63 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 47403225 + 34187409 = 6885^2 + 5847^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2266389 + ... + 2266424.

Almost surely, 2^81590634 is an apocalyptic number.

81590634 is an abundant number, since it is smaller than the sum of its proper divisors (95189112).

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

81590634 is a wasteful number, since it uses less digits than its factorization.

81590634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4532821 (or 4532818 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 81590634 is about 9032.7534008186. The cubic root of 81590634 is about 433.7239815857.

The spelling of 81590634 in words is "eighty-one million, five hundred ninety thousand, six hundred thirty-four".