81698180265 has 96 divisors (see below), whose sum is σ = 154859402880. Its totient is φ = 39839589504.

The previous prime is 81698180233. The next prime is 81698180269. The reversal of 81698180265 is 56208189618.

It is a happy number.

It is not a de Polignac number, because 81698180265 - 2⁵ = 81698180233 is a prime.

It is a super-2 number, since 2×81698180265² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81698180269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10574694 + ... + 10582416.

It is an arithmetic number, because the mean of its divisors is an integer number (1613118780).

Almost surely, 2^81698180265 is an apocalyptic number.

It is an amenable number.

81698180265 is a deficient number, since it is larger than the sum of its proper divisors (73161222615).

81698180265 is a wasteful number, since it uses less digits than its factorization.

81698180265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7880 (or 7851 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 54.

The spelling of 81698180265 in words is "eighty-one billion, six hundred ninety-eight million, one hundred eighty thousand, two hundred sixty-five".