21422242157 has 2 divisors, whose sum is σ = 21422242158. Its totient is φ = 21422242156.

The previous prime is 21422242063. The next prime is 21422242211. The reversal of 21422242157 is 75124222412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18723543556 + 2698698601 = 136834^2 + 51949^2 .

It is a cyclic number.

It is not a de Polignac number, because 21422242157 - 2¹⁰ = 21422241133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21422242357) 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, 10711121078 + 10711121079.

It is an arithmetic number, because the mean of its divisors is an integer number (10711121079).

Almost surely, 2^21422242157 is an apocalyptic number.

It is an amenable number.

21422242157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422242157 is an equidigital number, since it uses as much as digits as its factorization.

21422242157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17920, while the sum is 32.

Adding to 21422242157 its reverse (75124222412), we get a palindrome (96546464569).

The spelling of 21422242157 in words is "twenty-one billion, four hundred twenty-two million, two hundred forty-two thousand, one hundred fifty-seven".