81051144 has 32 divisors (see below), whose sum is σ = 202849920. Its totient is φ = 26987456.

The previous prime is 81051133. The next prime is 81051161. The reversal of 81051144 is 44115018.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38257 + ... + 40319.

It is an arithmetic number, because the mean of its divisors is an integer number (6339060).

Almost surely, 2^81051144 is an apocalyptic number.

It is an amenable number.

81051144 is an abundant number, since it is smaller than the sum of its proper divisors (121798776).

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

81051144 is a wasteful number, since it uses less digits than its factorization.

81051144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3709 (or 3705 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 81051144 is about 9002.8408849651. The cubic root of 81051144 is about 432.7659166388.

The spelling of 81051144 in words is "eighty-one million, fifty-one thousand, one hundred forty-four".