81974316212 has 12 divisors (see below), whose sum is σ = 145183428096. Its totient is φ = 40493336760.

The previous prime is 81974316197. The next prime is 81974316233. The reversal of 81974316212 is 21261347918.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123454964 + ... + 123455627.

It is an arithmetic number, because the mean of its divisors is an integer number (12098619008).

Almost surely, 2^81974316212 is an apocalyptic number.

It is an amenable number.

81974316212 is a deficient number, since it is larger than the sum of its proper divisors (63209111884).

81974316212 is a wasteful number, since it uses less digits than its factorization.

81974316212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246910678 (or 246910676 counting only the distinct ones).

The product of its digits is 145152, while the sum is 44.

The spelling of 81974316212 in words is "eighty-one billion, nine hundred seventy-four million, three hundred sixteen thousand, two hundred twelve".