25440661 has 2 divisors, whose sum is σ = 25440662. Its totient is φ = 25440660.

The previous prime is 25440659. The next prime is 25440671. The reversal of 25440661 is 16604452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22146436 + 3294225 = 4706^2 + 1815^2 .

It is a cyclic number.

It is not a de Polignac number, because 25440661 - 2¹ = 25440659 is a prime.

Together with 25440659, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25440671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12720330 + 12720331.

It is an arithmetic number, because the mean of its divisors is an integer number (12720331).

Almost surely, 2^25440661 is an apocalyptic number.

It is an amenable number.

25440661 is a deficient number, since it is larger than the sum of its proper divisors (1).

25440661 is an equidigital number, since it uses as much as digits as its factorization.

25440661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 25440661 is about 5043.8736106290. The cubic root of 25440661 is about 294.1097782154.

The spelling of 25440661 in words is "twenty-five million, four hundred forty thousand, six hundred sixty-one".