1231898159 has 2 divisors, whose sum is σ = 1231898160. Its totient is φ = 1231898158.

The previous prime is 1231898137. The next prime is 1231898167. The reversal of 1231898159 is 9518981321.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1231898159 - 2²⁴ = 1215120943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231898359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615949079 + 615949080.

It is an arithmetic number, because the mean of its divisors is an integer number (615949080).

Almost surely, 2^1231898159 is an apocalyptic number.

1231898159 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231898159 is an equidigital number, since it uses as much as digits as its factorization.

1231898159 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 47.

The square root of 1231898159 is about 35098.4067872033. The cubic root of 1231898159 is about 1071.9921424830.

The spelling of 1231898159 in words is "one billion, two hundred thirty-one million, eight hundred ninety-eight thousand, one hundred fifty-nine".