81981662602 has 64 divisors (see below), whose sum is σ = 145474689024. Its totient is φ = 33926999040.

The previous prime is 81981662579. The next prime is 81981662611. The reversal of 81981662602 is 20626618918.

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 31 ways as a sum of consecutive naturals, for example, 13899318 + ... + 13905214.

It is an arithmetic number, because the mean of its divisors is an integer number (2273042016).

Almost surely, 2^81981662602 is an apocalyptic number.

81981662602 is a deficient number, since it is larger than the sum of its proper divisors (63493026422).

81981662602 is a wasteful number, since it uses less digits than its factorization.

81981662602 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6263.

The product of its (nonzero) digits is 497664, while the sum is 49.

The spelling of 81981662602 in words is "eighty-one billion, nine hundred eighty-one million, six hundred sixty-two thousand, six hundred two".