81124864 has 60 divisors (see below), whose sum is σ = 171201096. Its totient is φ = 38331392.

The previous prime is 81124859. The next prime is 81124891. The reversal of 81124864 is 46842118.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 977367 + ... + 977449.

Almost surely, 2^81124864 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 81124864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85600548).

81124864 is an abundant number, since it is smaller than the sum of its proper divisors (90076232).

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

81124864 is an frugal number, since it uses more digits than its factorization.

81124864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 108 counting only the distinct ones).

The product of its digits is 12288, while the sum is 34.

The square root of 81124864 is about 9006.9342175904. The cubic root of 81124864 is about 432.8970841712.

It can be divided in two parts, 8 and 1124864, that multiplied together give a cube (8998912 = 208³).

The spelling of 81124864 in words is "eighty-one million, one hundred twenty-four thousand, eight hundred sixty-four".