21012022219957 has 2 divisors, whose sum is σ = 21012022219958. Its totient is φ = 21012022219956.

The previous prime is 21012022219927. The next prime is 21012022220009. The reversal of 21012022219957 is 75991222021012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10653865728676 + 10358156491281 = 3264026^2 + 3218409^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012022219957 - 2³¹ = 21009874736309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012022219927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506011109978 + 10506011109979.

It is an arithmetic number, because the mean of its divisors is an integer number (10506011109979).

Almost surely, 2^{21012022219957} is an apocalyptic number.

It is an amenable number.

21012022219957 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012022219957 is an equidigital number, since it uses as much as digits as its factorization.

21012022219957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 43.

The spelling of 21012022219957 in words is "twenty-one trillion, twelve billion, twenty-two million, two hundred nineteen thousand, nine hundred fifty-seven".