81113215242 has 16 divisors (see below), whose sum is σ = 163714747680. Its totient is φ = 26789685552.

The previous prime is 81113215207. The next prime is 81113215247. The reversal of 81113215242 is 24251231118.

It is a happy number.

It is a super-2 number, since 2×81113215242² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81113215247) 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 7 ways as a sum of consecutive naturals, for example, 62012508 + ... + 62013815.

It is an arithmetic number, because the mean of its divisors is an integer number (10232171730).

Almost surely, 2^81113215242 is an apocalyptic number.

81113215242 is an abundant number, since it is smaller than the sum of its proper divisors (82601532438).

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

81113215242 is a wasteful number, since it uses less digits than its factorization.

81113215242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124026437.

The product of its digits is 3840, while the sum is 30.

The spelling of 81113215242 in words is "eighty-one billion, one hundred thirteen million, two hundred fifteen thousand, two hundred forty-two".