81858156 has 24 divisors (see below), whose sum is σ = 201055680. Its totient is φ = 25849872.

The previous prime is 81858151. The next prime is 81858163. The reversal of 81858156 is 65185818.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81858151) 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, 179286 + ... + 179741.

It is an arithmetic number, because the mean of its divisors is an integer number (8377320).

Almost surely, 2^81858156 is an apocalyptic number.

It is an amenable number.

81858156 is an abundant number, since it is smaller than the sum of its proper divisors (119197524).

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

81858156 is a wasteful number, since it uses less digits than its factorization.

81858156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359053 (or 359051 counting only the distinct ones).

The product of its digits is 76800, while the sum is 42.

The square root of 81858156 is about 9047.5497235439. The cubic root of 81858156 is about 434.1975004883.

The spelling of 81858156 in words is "eighty-one million, eight hundred fifty-eight thousand, one hundred fifty-six".