123542521391 has 2 divisors, whose sum is σ = 123542521392. Its totient is φ = 123542521390.

The previous prime is 123542521339. The next prime is 123542521409. The reversal of 123542521391 is 193125245321.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 123542521391 - 2⁶ = 123542521327 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123544521391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61771260695 + 61771260696.

It is an arithmetic number, because the mean of its divisors is an integer number (61771260696).

Almost surely, 2^123542521391 is an apocalyptic number.

123542521391 is a deficient number, since it is larger than the sum of its proper divisors (1).

123542521391 is an equidigital number, since it uses as much as digits as its factorization.

123542521391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64800, while the sum is 38.

The spelling of 123542521391 in words is "one hundred twenty-three billion, five hundred forty-two million, five hundred twenty-one thousand, three hundred ninety-one".