65006566021 has 2 divisors, whose sum is σ = 65006566022. Its totient is φ = 65006566020.

The previous prime is 65006565997. The next prime is 65006566061. The reversal of 65006566021 is 12066560056.

65006566021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50584957921 + 14421608100 = 224911^2 + 120090^2 .

It is a cyclic number.

It is not a de Polignac number, because 65006566021 - 2⁹ = 65006565509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65006566061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32503283010 + 32503283011.

It is an arithmetic number, because the mean of its divisors is an integer number (32503283011).

Almost surely, 2^65006566021 is an apocalyptic number.

It is an amenable number.

65006566021 is a deficient number, since it is larger than the sum of its proper divisors (1).

65006566021 is an equidigital number, since it uses as much as digits as its factorization.

65006566021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 37.

The spelling of 65006566021 in words is "sixty-five billion, six million, five hundred sixty-six thousand, twenty-one".