1581491413 has 2 divisors, whose sum is σ = 1581491414. Its totient is φ = 1581491412.

The previous prime is 1581491399. The next prime is 1581491459. The reversal of 1581491413 is 3141941851.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 891798769 + 689692644 = 29863^2 + 26262^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1581491413 is a prime.

It is a super-3 number, since 3×1581491413³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1582491413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 790745706 + 790745707.

It is an arithmetic number, because the mean of its divisors is an integer number (790745707).

Almost surely, 2^1581491413 is an apocalyptic number.

It is an amenable number.

1581491413 is a deficient number, since it is larger than the sum of its proper divisors (1).

1581491413 is an equidigital number, since it uses as much as digits as its factorization.

1581491413 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 37.

The square root of 1581491413 is about 39767.9696866712. The cubic root of 1581491413 is about 1165.0796394193.

The spelling of 1581491413 in words is "one billion, five hundred eighty-one million, four hundred ninety-one thousand, four hundred thirteen".