81894624 has 48 divisors (see below), whose sum is σ = 245685888. Its totient is φ = 23398272.

The previous prime is 81894611. The next prime is 81894641. The reversal of 81894624 is 42649818.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60262 + ... + 61605.

It is an arithmetic number, because the mean of its divisors is an integer number (5118456).

Almost surely, 2^81894624 is an apocalyptic number.

81894624 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

81894624 is an abundant number, since it is smaller than the sum of its proper divisors (163791264).

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

81894624 is a wasteful number, since it uses less digits than its factorization.

81894624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121887 (or 121879 counting only the distinct ones).

The product of its digits is 110592, while the sum is 42.

The square root of 81894624 is about 9049.5648514169. The cubic root of 81894624 is about 434.2619695829.

The spelling of 81894624 in words is "eighty-one million, eight hundred ninety-four thousand, six hundred twenty-four".