1590817561 has 2 divisors, whose sum is σ = 1590817562. Its totient is φ = 1590817560.

The previous prime is 1590817499. The next prime is 1590817567. The reversal of 1590817561 is 1657180951.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1139467536 + 451350025 = 33756^2 + 21245^2 .

It is an emirp because it is prime and its reverse (1657180951) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1590817561 - 2¹³ = 1590809369 is a prime.

It is not a weakly prime, because it can be changed into another prime (1590817567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 795408780 + 795408781.

It is an arithmetic number, because the mean of its divisors is an integer number (795408781).

Almost surely, 2^1590817561 is an apocalyptic number.

It is an amenable number.

1590817561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1590817561 is an equidigital number, since it uses as much as digits as its factorization.

1590817561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 43.

The square root of 1590817561 is about 39885.0543562372. The cubic root of 1590817561 is about 1167.3653334151.

The spelling of 1590817561 in words is "one billion, five hundred ninety million, eight hundred seventeen thousand, five hundred sixty-one".