81894588 has 24 divisors (see below), whose sum is σ = 191638608. Its totient is φ = 27219456.

The previous prime is 81894587. The next prime is 81894599. The reversal of 81894588 is 88549818.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81894588.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81894581) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5431 + ... + 13902.

It is an arithmetic number, because the mean of its divisors is an integer number (7984942).

Almost surely, 2^81894588 is an apocalyptic number.

It is an amenable number.

81894588 is an abundant number, since it is smaller than the sum of its proper divisors (109744020).

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

81894588 is a wasteful number, since it uses less digits than its factorization.

81894588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19693 (or 19691 counting only the distinct ones).

The product of its digits is 737280, while the sum is 51.

The square root of 81894588 is about 9049.5628623708. The cubic root of 81894588 is about 434.2619059506.

The spelling of 81894588 in words is "eighty-one million, eight hundred ninety-four thousand, five hundred eighty-eight".