1981522818894 has 32 divisors (see below), whose sum is σ = 4038139505664. Its totient is φ = 647993933600.

The previous prime is 1981522818839. The next prime is 1981522818917. The reversal of 1981522818894 is 4988182251891.

It is a congruent number.

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, 3888619 + ... + 4368569.

It is an arithmetic number, because the mean of its divisors is an integer number (126191859552).

Almost surely, 2^{1981522818894} is an apocalyptic number.

1981522818894 is an abundant number, since it is smaller than the sum of its proper divisors (2056616686770).

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

1981522818894 is a wasteful number, since it uses less digits than its factorization.

1981522818894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492992.

The product of its digits is 26542080, while the sum is 66.

The spelling of 1981522818894 in words is "one trillion, nine hundred eighty-one billion, five hundred twenty-two million, eight hundred eighteen thousand, eight hundred ninety-four".