81958404 has 96 divisors (see below), whose sum is σ = 217719936. Its totient is φ = 23777280.

The previous prime is 81958403. The next prime is 81958417. The reversal of 81958404 is 40485918.

It is not an unprimeable number, because it can be changed into a prime (81958403) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 473662 + ... + 473834.

It is an arithmetic number, because the mean of its divisors is an integer number (2267916).

Almost surely, 2^81958404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81958404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108859968).

81958404 is an abundant number, since it is smaller than the sum of its proper divisors (135761532).

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

81958404 is a wasteful number, since it uses less digits than its factorization.

81958404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325 (or 323 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 39.

The square root of 81958404 is about 9053.0880919165. The cubic root of 81958404 is about 434.3746755618.

The spelling of 81958404 in words is "eighty-one million, nine hundred fifty-eight thousand, four hundred four".