1591132321 has 9 divisors (see below), whose sum is σ = 1609898329. Its totient is φ = 1572583936.

The previous prime is 1591132307. The next prime is 1591132331. The reversal of 1591132321 is 1232311951.

The square root of 1591132321 is 39889.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 733813921 + 857318400 = 27089^2 + 29280^2 .

It is not a de Polignac number, because 1591132321 - 2¹⁵ = 1591099553 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1591132321.

It is not an unprimeable number, because it can be changed into a prime (1591132331) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4507281 + ... + 4507633.

Almost surely, 2^1591132321 is an apocalyptic number.

1591132321 is the 39889-th square number.

1591132321 is the 19945-th centered octagonal number.

It is an amenable number.

1591132321 is a deficient number, since it is larger than the sum of its proper divisors (18766008).

1591132321 is an frugal number, since it uses more digits than its factorization.

1591132321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932 (or 466 counting only the distinct ones).

The product of its digits is 1620, while the sum is 28.

The cubic root of 1591132321 is about 1167.4423201775.

The spelling of 1591132321 in words is "one billion, five hundred ninety-one million, one hundred thirty-two thousand, three hundred twenty-one".