2131609 has 2 divisors, whose sum is σ = 2131610. Its totient is φ = 2131608.

The previous prime is 2131603. The next prime is 2131627. The reversal of 2131609 is 9061312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2131600 + 9 = 1460^2 + 3^2 .

It is a cyclic number.

It is not a de Polignac number, because 2131609 - 2³ = 2131601 is a prime.

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 2131609.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2131601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1065804 + 1065805.

It is an arithmetic number, because the mean of its divisors is an integer number (1065805).

2^2131609 is an apocalyptic number.

It is an amenable number.

2131609 is a deficient number, since it is larger than the sum of its proper divisors (1).

2131609 is an equidigital number, since it uses as much as digits as its factorization.

2131609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 2131609 is about 1460.0030821885. The cubic root of 2131609 is about 128.6972247333.

The spelling of 2131609 in words is "two million, one hundred thirty-one thousand, six hundred nine".