1581491459 has 2 divisors, whose sum is σ = 1581491460. Its totient is φ = 1581491458.

The previous prime is 1581491413. The next prime is 1581491489. The reversal of 1581491459 is 9541941851.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1581491459 is a prime.

It is a super-2 number, since 2×1581491459² = 5002230469779897362, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1581491489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 790745729 + 790745730.

It is an arithmetic number, because the mean of its divisors is an integer number (790745730).

Almost surely, 2^1581491459 is an apocalyptic number.

1581491459 is a deficient number, since it is larger than the sum of its proper divisors (1).

1581491459 is an equidigital number, since it uses as much as digits as its factorization.

1581491459 is an evil number, because the sum of its binary digits is even.

The product of its digits is 259200, while the sum is 47.

The square root of 1581491459 is about 39767.9702650261. The cubic root of 1581491459 is about 1165.0796507153.

The spelling of 1581491459 in words is "one billion, five hundred eighty-one million, four hundred ninety-one thousand, four hundred fifty-nine".