123442157 has 2 divisors, whose sum is σ = 123442158. Its totient is φ = 123442156.

The previous prime is 123442153. The next prime is 123442169. The reversal of 123442157 is 751244321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91508356 + 31933801 = 9566^2 + 5651^2 .

It is an emirp because it is prime and its reverse (751244321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123442157 - 2² = 123442153 is a prime.

It is a super-2 number, since 2×123442157² = 30475932249625298, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123442153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61721078 + 61721079.

It is an arithmetic number, because the mean of its divisors is an integer number (61721079).

Almost surely, 2^123442157 is an apocalyptic number.

It is an amenable number.

123442157 is a deficient number, since it is larger than the sum of its proper divisors (1).

123442157 is an equidigital number, since it uses as much as digits as its factorization.

123442157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 29.

The square root of 123442157 is about 11110.4526010420. The cubic root of 123442157 is about 497.9141868666.

Adding to 123442157 its reverse (751244321), we get a palindrome (874686478).

The spelling of 123442157 in words is "one hundred twenty-three million, four hundred forty-two thousand, one hundred fifty-seven".