123712891 has 2 divisors, whose sum is σ = 123712892. Its totient is φ = 123712890.

The previous prime is 123712877. The next prime is 123712903. The reversal of 123712891 is 198217321.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123712891 is a prime.

It is not a weakly prime, because it can be changed into another prime (123712871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61856445 + 61856446.

It is an arithmetic number, because the mean of its divisors is an integer number (61856446).

Almost surely, 2^123712891 is an apocalyptic number.

123712891 is a deficient number, since it is larger than the sum of its proper divisors (1).

123712891 is an equidigital number, since it uses as much as digits as its factorization.

123712891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 34.

The square root of 123712891 is about 11122.6296800712. The cubic root of 123712891 is about 498.2779304286.

The spelling of 123712891 in words is "one hundred twenty-three million, seven hundred twelve thousand, eight hundred ninety-one".