25643389 has 2 divisors, whose sum is σ = 25643390. Its totient is φ = 25643388.

The previous prime is 25643383. The next prime is 25643419. The reversal of 25643389 is 98334652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25583364 + 60025 = 5058^2 + 245^2 .

It is a cyclic number.

It is not a de Polignac number, because 25643389 - 2⁵ = 25643357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25643383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12821694 + 12821695.

It is an arithmetic number, because the mean of its divisors is an integer number (12821695).

Almost surely, 2^25643389 is an apocalyptic number.

It is an amenable number.

25643389 is a deficient number, since it is larger than the sum of its proper divisors (1).

25643389 is an equidigital number, since it uses as much as digits as its factorization.

25643389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 40.

The square root of 25643389 is about 5063.9301930418. The cubic root of 25643389 is about 294.8889326211. Note that the first 3 decimals are identical.

The spelling of 25643389 in words is "twenty-five million, six hundred forty-three thousand, three hundred eighty-nine".