81757380085 has 16 divisors (see below), whose sum is σ = 98636700672. Its totient is φ = 65054404800.

The previous prime is 81757380079. The next prime is 81757380091. The reversal of 81757380085 is 58008375718.

It is an interprime number because it is at equal distance from previous prime (81757380079) and next prime (81757380091).

It is not a de Polignac number, because 81757380085 - 2²⁹ = 81220509173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1686252 + ... + 1734058.

It is an arithmetic number, because the mean of its divisors is an integer number (6164793792).

Almost surely, 2^81757380085 is an apocalyptic number.

It is an amenable number.

81757380085 is a deficient number, since it is larger than the sum of its proper divisors (16879320587).

81757380085 is a wasteful number, since it uses less digits than its factorization.

81757380085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49644.

The product of its (nonzero) digits is 1881600, while the sum is 52.

The spelling of 81757380085 in words is "eighty-one billion, seven hundred fifty-seven million, three hundred eighty thousand, eighty-five".