81506376 has 96 divisors (see below), whose sum is σ = 256651200. Its totient is φ = 22884480.

The previous prime is 81506363. The next prime is 81506377. The reversal of 81506376 is 67360518.

81506376 is a `hidden beast` number, since 8 + 15 + 0 + 637 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81506376.

It is not an unprimeable number, because it can be changed into a prime (81506377) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28366 + ... + 31106.

It is an arithmetic number, because the mean of its divisors is an integer number (2673450).

Almost surely, 2^81506376 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 81506376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128325600).

81506376 is an abundant number, since it is smaller than the sum of its proper divisors (175144824).

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

81506376 is a wasteful number, since it uses less digits than its factorization.

81506376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2819 (or 2812 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 81506376 is about 9028.0881697068. The cubic root of 81506376 is about 433.5746290579.

The spelling of 81506376 in words is "eighty-one million, five hundred six thousand, three hundred seventy-six".