81761650 has 24 divisors (see below), whose sum is σ = 152623044. Its totient is φ = 32587200.

The previous prime is 81761639. The next prime is 81761671. The reversal of 81761650 is 5616718.

It can be written as a sum of positive squares in 6 ways, for example, as 44049769 + 37711881 = 6637^2 + 6141^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11860 + ... + 17440.

Almost surely, 2^81761650 is an apocalyptic number.

81761650 is a deficient number, since it is larger than the sum of its proper divisors (70861394).

81761650 is a wasteful number, since it uses less digits than its factorization.

81761650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5886 (or 5881 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 81761650 is about 9042.2148835338. The cubic root of 81761650 is about 434.0268021985.

The spelling of 81761650 in words is "eighty-one million, seven hundred sixty-one thousand, six hundred fifty".