2505691 has 2 divisors, whose sum is σ = 2505692. Its totient is φ = 2505690.

The previous prime is 2505683. The next prime is 2505707. The reversal of 2505691 is 1965052.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2505691 - 2³ = 2505683 is a prime.

2505691 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2505611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1252845 + 1252846.

It is an arithmetic number, because the mean of its divisors is an integer number (1252846).

2^2505691 is an apocalyptic number.

2505691 is a deficient number, since it is larger than the sum of its proper divisors (1).

2505691 is an equidigital number, since it uses as much as digits as its factorization.

2505691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 2505691 is about 1582.9374592826. The cubic root of 2505691 is about 135.8237877878.

The spelling of 2505691 in words is "two million, five hundred five thousand, six hundred ninety-one".