20957145049 has 2 divisors, whose sum is σ = 20957145050. Its totient is φ = 20957145048.

The previous prime is 20957145031. The next prime is 20957145061. The reversal of 20957145049 is 94054175902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20842119424 + 115025625 = 144368^2 + 10725^2 .

It is a cyclic number.

It is not a de Polignac number, because 20957145049 - 2¹⁷ = 20957013977 is a prime.

It is not a weakly prime, because it can be changed into another prime (20957145019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10478572524 + 10478572525.

It is an arithmetic number, because the mean of its divisors is an integer number (10478572525).

Almost surely, 2^20957145049 is an apocalyptic number.

It is an amenable number.

20957145049 is a deficient number, since it is larger than the sum of its proper divisors (1).

20957145049 is an equidigital number, since it uses as much as digits as its factorization.

20957145049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 453600, while the sum is 46.

The spelling of 20957145049 in words is "twenty billion, nine hundred fifty-seven million, one hundred forty-five thousand, forty-nine".