1631231557 has 2 divisors, whose sum is σ = 1631231558. Its totient is φ = 1631231556.

The previous prime is 1631231479. The next prime is 1631231573. The reversal of 1631231557 is 7551321361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 832264801 + 798966756 = 28849^2 + 28266^2 .

It is a cyclic number.

It is not a de Polignac number, because 1631231557 - 2⁷ = 1631231429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1631231857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 815615778 + 815615779.

It is an arithmetic number, because the mean of its divisors is an integer number (815615779).

Almost surely, 2^1631231557 is an apocalyptic number.

It is an amenable number.

1631231557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1631231557 is an equidigital number, since it uses as much as digits as its factorization.

1631231557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18900, while the sum is 34.

The square root of 1631231557 is about 40388.5077342553. The cubic root of 1631231557 is about 1177.1682450030.

The spelling of 1631231557 in words is "one billion, six hundred thirty-one million, two hundred thirty-one thousand, five hundred fifty-seven".