64021877021 has 2 divisors, whose sum is σ = 64021877022. Its totient is φ = 64021877020.

The previous prime is 64021876991. The next prime is 64021877041. The reversal of 64021877021 is 12077812046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62830936921 + 1190940100 = 250661^2 + 34510^2 .

It is a cyclic number.

It is not a de Polignac number, because 64021877021 - 2¹⁰ = 64021875997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64021877041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32010938510 + 32010938511.

It is an arithmetic number, because the mean of its divisors is an integer number (32010938511).

Almost surely, 2^64021877021 is an apocalyptic number.

It is an amenable number.

64021877021 is a deficient number, since it is larger than the sum of its proper divisors (1).

64021877021 is an equidigital number, since it uses as much as digits as its factorization.

64021877021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37632, while the sum is 38.

The spelling of 64021877021 in words is "sixty-four billion, twenty-one million, eight hundred seventy-seven thousand, twenty-one".