81351615318 has 16 divisors (see below), whose sum is σ = 165370497456. Its totient is φ = 26672660640.

The previous prime is 81351615263. The next prime is 81351615343.

It is a happy number.

81351615318 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×81351615318² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81351615318.

It is a congruent number.

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, 111135721 + ... + 111136452.

It is an arithmetic number, because the mean of its divisors is an integer number (10335656091).

Almost surely, 2^81351615318 is an apocalyptic number.

81351615318 is an abundant number, since it is smaller than the sum of its proper divisors (84018882138).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81351615318 is a wasteful number, since it uses less digits than its factorization.

81351615318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222272239.

The product of its digits is 86400, while the sum is 42.

The spelling of 81351615318 in words is "eighty-one billion, three hundred fifty-one million, six hundred fifteen thousand, three hundred eighteen".