7981564542021 has 48 divisors (see below), whose sum is σ = 13703354853760. Its totient is φ = 4381796684160.

The previous prime is 7981564541983. The next prime is 7981564542053. The reversal of 7981564542021 is 1202454651897.

7981564542021 is a `hidden beast` number, since 7 + 9 + 8 + 1 + 564 + 54 + 2 + 0 + 21 = 666.

It is not a de Polignac number, because 7981564542021 - 2¹³ = 7981564533829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7981564544021) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23984866 + ... + 24315363.

Almost surely, 2^{7981564542021} is an apocalyptic number.

It is an amenable number.

7981564542021 is a deficient number, since it is larger than the sum of its proper divisors (5721790311739).

7981564542021 is a wasteful number, since it uses less digits than its factorization.

7981564542021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48300346 (or 48300343 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 54.

The spelling of 7981564542021 in words is "seven trillion, nine hundred eighty-one billion, five hundred sixty-four million, five hundred forty-two thousand, twenty-one".