2540689 has 2 divisors, whose sum is σ = 2540690. Its totient is φ = 2540688.

The previous prime is 2540687. The next prime is 2540693. The reversal of 2540689 is 9860452.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2387025 + 153664 = 1545^2 + 392^2 .

It is a cyclic number.

It is not a de Polignac number, because 2540689 - 2¹ = 2540687 is a prime.

Together with 2540687, it forms a pair of twin primes.

It is equal to p₁₈₅₈₃₉ and since 2540689 and 185839 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (2540687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1270344 + 1270345.

It is an arithmetic number, because the mean of its divisors is an integer number (1270345).

2^2540689 is an apocalyptic number.

It is an amenable number.

2540689 is a deficient number, since it is larger than the sum of its proper divisors (1).

2540689 is an equidigital number, since it uses as much as digits as its factorization.

2540689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 2540689 is about 1593.9538889190. The cubic root of 2540689 is about 136.4532348398.

The spelling of 2540689 in words is "two million, five hundred forty thousand, six hundred eighty-nine".