81947294922 has 16 divisors (see below), whose sum is σ = 163931548032. Its totient is φ = 27309605280.

The previous prime is 81947294917. The next prime is 81947294927. The reversal of 81947294922 is 22949274918.

It is an interprime number because it is at equal distance from previous prime (81947294917) and next prime (81947294927).

It is not an unprimeable number, because it can be changed into a prime (81947294927) 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, 1511058 + ... + 1564349.

It is an arithmetic number, because the mean of its divisors is an integer number (10245721752).

Almost surely, 2^81947294922 is an apocalyptic number.

81947294922 is an abundant number, since it is smaller than the sum of its proper divisors (81984253110).

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

81947294922 is a wasteful number, since it uses less digits than its factorization.

81947294922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3079853.

The product of its digits is 5225472, while the sum is 57.

The spelling of 81947294922 in words is "eighty-one billion, nine hundred forty-seven million, two hundred ninety-four thousand, nine hundred twenty-two".