81113213784 has 32 divisors (see below), whose sum is σ = 203312517120. Its totient is φ = 26967140256.

The previous prime is 81113213771. The next prime is 81113213807. The reversal of 81113213784 is 48731231118.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4402972 + ... + 4421355.

It is an arithmetic number, because the mean of its divisors is an integer number (6353516160).

Almost surely, 2^81113213784 is an apocalyptic number.

It is an amenable number.

81113213784 is an abundant number, since it is smaller than the sum of its proper divisors (122199303336).

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

81113213784 is a wasteful number, since it uses less digits than its factorization.

81113213784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8824719 (or 8824715 counting only the distinct ones).

The product of its digits is 32256, while the sum is 39.

The spelling of 81113213784 in words is "eighty-one billion, one hundred thirteen million, two hundred thirteen thousand, seven hundred eighty-four".