81574374 has 64 divisors (see below), whose sum is σ = 191116800. Its totient is φ = 22733568.

The previous prime is 81574343. The next prime is 81574393. The reversal of 81574374 is 47347518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 519504 + ... + 519660.

It is an arithmetic number, because the mean of its divisors is an integer number (2986200).

Almost surely, 2^81574374 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81574374, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95558400).

81574374 is an abundant number, since it is smaller than the sum of its proper divisors (109542426).

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

81574374 is a wasteful number, since it uses less digits than its factorization.

81574374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397.

The product of its digits is 94080, while the sum is 39.

The square root of 81574374 is about 9031.8532981886. The cubic root of 81574374 is about 433.6951677373.

The spelling of 81574374 in words is "eighty-one million, five hundred seventy-four thousand, three hundred seventy-four".