1231587157 has 2 divisors, whose sum is σ = 1231587158. Its totient is φ = 1231587156.

The previous prime is 1231587139. The next prime is 1231587193. The reversal of 1231587157 is 7517851321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1229624356 + 1962801 = 35066^2 + 1401^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231587157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231587197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615793578 + 615793579.

It is an arithmetic number, because the mean of its divisors is an integer number (615793579).

Almost surely, 2^1231587157 is an apocalyptic number.

It is an amenable number.

1231587157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231587157 is an equidigital number, since it uses as much as digits as its factorization.

1231587157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58800, while the sum is 40.

The square root of 1231587157 is about 35093.9760785238. The cubic root of 1231587157 is about 1071.9019240512.

The spelling of 1231587157 in words is "one billion, two hundred thirty-one million, five hundred eighty-seven thousand, one hundred fifty-seven".