123220042242391 has 2 divisors, whose sum is σ = 123220042242392. Its totient is φ = 123220042242390.

The previous prime is 123220042242389. The next prime is 123220042242397. The reversal of 123220042242391 is 193242240022321.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 123220042242391 - 2¹ = 123220042242389 is a prime.

Together with 123220042242389, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 123220042242391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123220042242397) 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, 61610021121195 + 61610021121196.

It is an arithmetic number, because the mean of its divisors is an integer number (61610021121196).

Almost surely, 2^{123220042242391} is an apocalyptic number.

123220042242391 is a deficient number, since it is larger than the sum of its proper divisors (1).

123220042242391 is an equidigital number, since it uses as much as digits as its factorization.

123220042242391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 37.

The spelling of 123220042242391 in words is "one hundred twenty-three trillion, two hundred twenty billion, forty-two million, two hundred forty-two thousand, three hundred ninety-one".