81818657874 has 32 divisors (see below), whose sum is σ = 181844360640. Its totient is φ = 27269117856.

The previous prime is 81818657857. The next prime is 81818657891. The reversal of 81818657874 is 47875681818.

It is an interprime number because it is at equal distance from previous prime (81818657857) and next prime (81818657891).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 304462 + ... + 506294.

It is an arithmetic number, because the mean of its divisors is an integer number (5682636270).

Almost surely, 2^81818657874 is an apocalyptic number.

81818657874 is an abundant number, since it is smaller than the sum of its proper divisors (100025702766).

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

81818657874 is a wasteful number, since it uses less digits than its factorization.

81818657874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209351 (or 209345 counting only the distinct ones).

The product of its digits is 24084480, while the sum is 63.

The spelling of 81818657874 in words is "eighty-one billion, eight hundred eighteen million, six hundred fifty-seven thousand, eight hundred seventy-four".