21210322204957 has 2 divisors, whose sum is σ = 21210322204958. Its totient is φ = 21210322204956.

The previous prime is 21210322204829. The next prime is 21210322204987. The reversal of 21210322204957 is 75940222301212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20846995354201 + 363326850756 = 4565851^2 + 602766^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210322204957 - 2⁷ = 21210322204829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210322204987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605161102478 + 10605161102479.

It is an arithmetic number, because the mean of its divisors is an integer number (10605161102479).

Almost surely, 2^{21210322204957} is an apocalyptic number.

It is an amenable number.

21210322204957 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210322204957 is an equidigital number, since it uses as much as digits as its factorization.

21210322204957 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 21210322204957 in words is "twenty-one trillion, two hundred ten billion, three hundred twenty-two million, two hundred four thousand, nine hundred fifty-seven".