81438876 has 18 divisors (see below), whose sum is σ = 205859472. Its totient is φ = 27146280.

The previous prime is 81438839. The next prime is 81438881. The reversal of 81438876 is 67883418.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1131060 + ... + 1131131.

Almost surely, 2^81438876 is an apocalyptic number.

It is an amenable number.

81438876 is an abundant number, since it is smaller than the sum of its proper divisors (124420596).

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

81438876 is a wasteful number, since it uses less digits than its factorization.

81438876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2262201 (or 2262196 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The square root of 81438876 is about 9024.3490623978. The cubic root of 81438876 is about 433.4549068487.

The spelling of 81438876 in words is "eighty-one million, four hundred thirty-eight thousand, eight hundred seventy-six".