81565187151 has 32 divisors (see below), whose sum is σ = 126785640960. Its totient is φ = 45679810176.

The previous prime is 81565187149. The next prime is 81565187161. The reversal of 81565187151 is 15178156518.

It is not a de Polignac number, because 81565187151 - 2¹ = 81565187149 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81565187151.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81565187161) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 130045 + ... + 424313.

It is an arithmetic number, because the mean of its divisors is an integer number (3962051280).

Almost surely, 2^81565187151 is an apocalyptic number.

81565187151 is a deficient number, since it is larger than the sum of its proper divisors (45220453809).

81565187151 is a wasteful number, since it uses less digits than its factorization.

81565187151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294543.

The product of its digits is 336000, while the sum is 48.

The spelling of 81565187151 in words is "eighty-one billion, five hundred sixty-five million, one hundred eighty-seven thousand, one hundred fifty-one".