1258231561 has 2 divisors, whose sum is σ = 1258231562. Its totient is φ = 1258231560.

The previous prime is 1258231519. The next prime is 1258231571. The reversal of 1258231561 is 1651328521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 954810000 + 303421561 = 30900^2 + 17419^2 .

It is a cyclic number.

It is not a de Polignac number, because 1258231561 - 2¹⁷ = 1258100489 is a prime.

It is a super-2 number, since 2×1258231561² = 3166293322192993442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1258231571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 629115780 + 629115781.

It is an arithmetic number, because the mean of its divisors is an integer number (629115781).

Almost surely, 2^1258231561 is an apocalyptic number.

It is an amenable number.

1258231561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1258231561 is an equidigital number, since it uses as much as digits as its factorization.

1258231561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 34.

The square root of 1258231561 is about 35471.5598895791. The cubic root of 1258231561 is about 1079.5767548793.

The spelling of 1258231561 in words is "one billion, two hundred fifty-eight million, two hundred thirty-one thousand, five hundred sixty-one".