81565887350 has 24 divisors (see below), whose sum is σ = 151764973920. Its totient is φ = 32615081120.

The previous prime is 81565887349. The next prime is 81565887397. The reversal of 81565887350 is 5378856518.

It is a happy number.

It is a hoax number, since the sum of its digits (56) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 134942 + ... + 425841.

It is an arithmetic number, because the mean of its divisors is an integer number (6323540580).

Almost surely, 2^81565887350 is an apocalyptic number.

81565887350 is a deficient number, since it is larger than the sum of its proper divisors (70199086570).

81565887350 is a wasteful number, since it uses less digits than its factorization.

81565887350 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 563704 (or 563699 counting only the distinct ones).

The product of its (nonzero) digits is 8064000, while the sum is 56.

The spelling of 81565887350 in words is "eighty-one billion, five hundred sixty-five million, eight hundred eighty-seven thousand, three hundred fifty".