81953574 has 32 divisors (see below), whose sum is σ = 173076480. Its totient is φ = 25798752.

The previous prime is 81953567. The next prime is 81953587. The reversal of 81953574 is 47535918.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42724 + ... + 44600.

It is an arithmetic number, because the mean of its divisors is an integer number (5408640).

Almost surely, 2^81953574 is an apocalyptic number.

81953574 is an abundant number, since it is smaller than the sum of its proper divisors (91122906).

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

81953574 is a wasteful number, since it uses less digits than its factorization.

81953574 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2284.

The product of its digits is 151200, while the sum is 42.

The square root of 81953574 is about 9052.8213281827. The cubic root of 81953574 is about 434.3661424897.

The spelling of 81953574 in words is "eighty-one million, nine hundred fifty-three thousand, five hundred seventy-four".