81725260205765 has 32 divisors (see below), whose sum is σ = 110491116871680. Its totient is φ = 57491032737600.

The previous prime is 81725260205707. The next prime is 81725260205777. The reversal of 81725260205765 is 56750206252718.

It is a de Polignac number, because none of the positive numbers 2^k-81725260205765 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81725260205765.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8277479 + ... + 15230468.

It is an arithmetic number, because the mean of its divisors is an integer number (3452847402240).

Almost surely, 2^{81725260205765} is an apocalyptic number.

It is an amenable number.

81725260205765 is a deficient number, since it is larger than the sum of its proper divisors (28765856665915).

81725260205765 is a wasteful number, since it uses less digits than its factorization.

81725260205765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23510033.

The product of its (nonzero) digits is 14112000, while the sum is 56.

The spelling of 81725260205765 in words is "eighty-one trillion, seven hundred twenty-five billion, two hundred sixty million, two hundred five thousand, seven hundred sixty-five".