123551423222561 has 2 divisors, whose sum is σ = 123551423222562. Its totient is φ = 123551423222560.

The previous prime is 123551423222519. The next prime is 123551423222599. The reversal of 123551423222561 is 165222324155321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122060093782561 + 1491329440000 = 11048081^2 + 1221200^2 .

It is a cyclic number.

It is not a de Polignac number, because 123551423222561 - 2²⁶ = 123551356113697 is a prime.

It is not a weakly prime, because it can be changed into another prime (123551423222261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61775711611280 + 61775711611281.

It is an arithmetic number, because the mean of its divisors is an integer number (61775711611281).

Almost surely, 2^{123551423222561} is an apocalyptic number.

It is an amenable number.

123551423222561 is a deficient number, since it is larger than the sum of its proper divisors (1).

123551423222561 is an equidigital number, since it uses as much as digits as its factorization.

123551423222561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864000, while the sum is 44.

Adding to 123551423222561 its reverse (165222324155321), we get a palindrome (288773747377882).

The spelling of 123551423222561 in words is "one hundred twenty-three trillion, five hundred fifty-one billion, four hundred twenty-three million, two hundred twenty-two thousand, five hundred sixty-one".