1591969 has 2 divisors, whose sum is σ = 1591970. Its totient is φ = 1591968.

The previous prime is 1591949. The next prime is 1591973. The reversal of 1591969 is 9691951.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1411344 + 180625 = 1188^2 + 425^2 .

It is a cyclic number.

It is not a de Polignac number, because 1591969 - 2⁷ = 1591841 is a prime.

It is a super-2 number, since 2×1591969² = 5068730593922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1591949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 795984 + 795985.

It is an arithmetic number, because the mean of its divisors is an integer number (795985).

2^1591969 is an apocalyptic number.

It is an amenable number.

1591969 is a deficient number, since it is larger than the sum of its proper divisors (1).

1591969 is an equidigital number, since it uses as much as digits as its factorization.

1591969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21870, while the sum is 40.

The square root of 1591969 is about 1261.7325390113. The cubic root of 1591969 is about 116.7646913117.

The spelling of 1591969 in words is "one million, five hundred ninety-one thousand, nine hundred sixty-nine".