81609174 has 32 divisors (see below), whose sum is σ = 187207680. Its totient is φ = 26325000.

The previous prime is 81609167. The next prime is 81609191. The reversal of 81609174 is 47190618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22702 + ... + 26049.

It is an arithmetic number, because the mean of its divisors is an integer number (5850240).

Almost surely, 2^81609174 is an apocalyptic number.

81609174 is an abundant number, since it is smaller than the sum of its proper divisors (105598506).

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

81609174 is a wasteful number, since it uses less digits than its factorization.

81609174 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48793 (or 48787 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 81609174 is about 9033.7796076725. The cubic root of 81609174 is about 433.7568310817.

The spelling of 81609174 in words is "eighty-one million, six hundred nine thousand, one hundred seventy-four".