85404981565 has 64 divisors (see below), whose sum is σ = 113696526528. Its totient is φ = 61312204800.

The previous prime is 85404981553. The next prime is 85404981583. The reversal of 85404981565 is 56518940458.

It can be written as a sum of positive squares in 32 ways, for example, as 31124369241 + 54280612324 = 176421^2 + 232982^2 .

It is not a de Polignac number, because 85404981565 - 2⁵ = 85404981533 is a prime.

It is a super-2 number, since 2×85404981565² (a number of 23 digits) contains 22 as substring.

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 63 ways as a sum of consecutive naturals, for example, 64651105 + ... + 64652425.

It is an arithmetic number, because the mean of its divisors is an integer number (1776508227).

Almost surely, 2^85404981565 is an apocalyptic number.

85404981565 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

85404981565 is a deficient number, since it is larger than the sum of its proper divisors (28291544963).

85404981565 is a wasteful number, since it uses less digits than its factorization.

85404981565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1778.

The product of its (nonzero) digits is 6912000, while the sum is 55.

The spelling of 85404981565 in words is "eighty-five billion, four hundred four million, nine hundred eighty-one thousand, five hundred sixty-five".