21939222123157 has 2 divisors, whose sum is σ = 21939222123158. Its totient is φ = 21939222123156.

The previous prime is 21939222123029. The next prime is 21939222123197. The reversal of 21939222123157 is 75132122293912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12948093935716 + 8991128187441 = 3598346^2 + 2998521^2 .

It is a cyclic number.

It is not a de Polignac number, because 21939222123157 - 2⁷ = 21939222123029 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21939222123157.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21939222123197) 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, 10969611061578 + 10969611061579.

It is an arithmetic number, because the mean of its divisors is an integer number (10969611061579).

Almost surely, 2^{21939222123157} is an apocalyptic number.

It is an amenable number.

21939222123157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21939222123157 is an equidigital number, since it uses as much as digits as its factorization.

21939222123157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 816480, while the sum is 49.

The spelling of 21939222123157 in words is "twenty-one trillion, nine hundred thirty-nine billion, two hundred twenty-two million, one hundred twenty-three thousand, one hundred fifty-seven".