1591371664 has 15 divisors (see below), whose sum is σ = 3083591793. Its totient is φ = 795606048.

The previous prime is 1591371653. The next prime is 1591371667. The reversal of 1591371664 is 4661731951.

The square root of 1591371664 is 39892.

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

It can be written as a sum of positive squares in only one way, i.e., 193210000 + 1398161664 = 13900^2 + 37392^2 .

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 1591371664.

It is not an unprimeable number, because it can be changed into a prime (1591371667) 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 in 2 ways as a sum of consecutive naturals, for example, 154582 + ... + 164554.

Almost surely, 2^1591371664 is an apocalyptic number.

1591371664 is the 39892-nd square number.

It is an amenable number.

1591371664 is a deficient number, since it is larger than the sum of its proper divisors (1492220129).

1591371664 is an frugal number, since it uses more digits than its factorization.

1591371664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19954 (or 9975 counting only the distinct ones).

The product of its digits is 136080, while the sum is 43.

The cubic root of 1591371664 is about 1167.5008539932.

It can be divided in two parts, 159137 and 1664, that added together give a square (160801 = 401²).

The spelling of 1591371664 in words is "one billion, five hundred ninety-one million, three hundred seventy-one thousand, six hundred sixty-four".