81859152 has 20 divisors (see below), whose sum is σ = 211469600. Its totient is φ = 27286368.

The previous prime is 81859123. The next prime is 81859153. The reversal of 81859152 is 25195818.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 81859152.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81859153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 852652 + ... + 852747.

It is an arithmetic number, because the mean of its divisors is an integer number (10573480).

Almost surely, 2^81859152 is an apocalyptic number.

It is an amenable number.

81859152 is an abundant number, since it is smaller than the sum of its proper divisors (129610448).

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

81859152 is a wasteful number, since it uses less digits than its factorization.

81859152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1705410 (or 1705404 counting only the distinct ones).

The product of its digits is 28800, while the sum is 39.

The square root of 81859152 is about 9047.6047659035. The cubic root of 81859152 is about 434.1992614977.

The spelling of 81859152 in words is "eighty-one million, eight hundred fifty-nine thousand, one hundred fifty-two".