81315318842379 has 24 divisors (see below), whose sum is σ = 118667451695520. Its totient is φ = 53650842490368.

The previous prime is 81315318842281. The next prime is 81315318842423. The reversal of 81315318842379 is 97324881351318.

It is a happy number.

81315318842379 is a `hidden beast` number, since 8 + 1 + 3 + 1 + 5 + 318 + 84 + 237 + 9 = 666.

It is not a de Polignac number, because 81315318842379 - 2¹³ = 81315318834187 is a prime.

It is a super-2 number, since 2×81315318842379² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81315318843379) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 108541309 + ... + 109287905.

It is an arithmetic number, because the mean of its divisors is an integer number (4944477153980).

Almost surely, 2^{81315318842379} is an apocalyptic number.

81315318842379 is a deficient number, since it is larger than the sum of its proper divisors (37352132853141).

81315318842379 is a wasteful number, since it uses less digits than its factorization.

81315318842379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 871459 (or 871456 counting only the distinct ones).

The product of its digits is 34836480, while the sum is 63.

The spelling of 81315318842379 in words is "eighty-one trillion, three hundred fifteen billion, three hundred eighteen million, eight hundred forty-two thousand, three hundred seventy-nine".