81890152 has 16 divisors (see below), whose sum is σ = 161625600. Its totient is φ = 38790000.

The previous prime is 81890117. The next prime is 81890177. The reversal of 81890152 is 25109818.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 269224 + ... + 269527.

It is an arithmetic number, because the mean of its divisors is an integer number (10101600).

Almost surely, 2^81890152 is an apocalyptic number.

It is an amenable number.

81890152 is a deficient number, since it is larger than the sum of its proper divisors (79735448).

81890152 is a wasteful number, since it uses less digits than its factorization.

81890152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 538776 (or 538772 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 81890152 is about 9049.3177643400. The cubic root of 81890152 is about 434.2540648928.

The spelling of 81890152 in words is "eighty-one million, eight hundred ninety thousand, one hundred fifty-two".