81659495618 has 16 divisors (see below), whose sum is σ = 126448456704. Its totient is φ = 39510175680.

The previous prime is 81659495543. The next prime is 81659495623.

81659495618 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×81659495618² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (62).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1301546 + ... + 1362842.

It is an arithmetic number, because the mean of its divisors is an integer number (7903028544).

Almost surely, 2^81659495618 is an apocalyptic number.

81659495618 is a deficient number, since it is larger than the sum of its proper divisors (44788961086).

81659495618 is a wasteful number, since it uses less digits than its factorization.

81659495618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82817.

The product of its digits is 18662400, while the sum is 62.

The spelling of 81659495618 in words is "eighty-one billion, six hundred fifty-nine million, four hundred ninety-five thousand, six hundred eighteen".