21753753157 has 2 divisors, whose sum is σ = 21753753158. Its totient is φ = 21753753156.

The previous prime is 21753753149. The next prime is 21753753181. The reversal of 21753753157 is 75135735712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18157832001 + 3595921156 = 134751^2 + 59966^2 .

It is a cyclic number.

It is not a de Polignac number, because 21753753157 - 2³ = 21753753149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21753753137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10876876578 + 10876876579.

It is an arithmetic number, because the mean of its divisors is an integer number (10876876579).

Almost surely, 2^21753753157 is an apocalyptic number.

It is an amenable number.

21753753157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21753753157 is an equidigital number, since it uses as much as digits as its factorization.

21753753157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 771750, while the sum is 46.

The spelling of 21753753157 in words is "twenty-one billion, seven hundred fifty-three million, seven hundred fifty-three thousand, one hundred fifty-seven".