81980420016 has 80 divisors (see below), whose sum is σ = 244626092928. Its totient is φ = 23381222400.

The previous prime is 81980419979. The next prime is 81980420017. The reversal of 81980420016 is 61002408918.

It is not an unprimeable number, because it can be changed into a prime (81980420017) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4557670 + ... + 4575621.

Almost surely, 2^81980420016 is an apocalyptic number.

It is an amenable number.

81980420016 is an abundant number, since it is smaller than the sum of its proper divisors (162645672912).

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

81980420016 is a wasteful number, since it uses less digits than its factorization.

81980420016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9133330 (or 9133324 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The spelling of 81980420016 in words is "eighty-one billion, nine hundred eighty million, four hundred twenty thousand, sixteen".