2521609 has 2 divisors, whose sum is σ = 2521610. Its totient is φ = 2521608.

The previous prime is 2521591. The next prime is 2521613. The reversal of 2521609 is 9061252.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1836025 + 685584 = 1355^2 + 828^2 .

It is a cyclic number.

It is not a de Polignac number, because 2521609 - 2⁷ = 2521481 is a prime.

2521609 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2531609) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1260804 + 1260805.

It is an arithmetic number, because the mean of its divisors is an integer number (1260805).

2^2521609 is an apocalyptic number.

It is an amenable number.

2521609 is a deficient number, since it is larger than the sum of its proper divisors (1).

2521609 is an equidigital number, since it uses as much as digits as its factorization.

2521609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 2521609 is about 1587.9574931339. The cubic root of 2521609 is about 136.1107985493.

It can be divided in two parts, 25 and 21609, that multiplied together give a square (540225 = 735²).

The spelling of 2521609 in words is "two million, five hundred twenty-one thousand, six hundred nine".