25605989 has 2 divisors, whose sum is σ = 25605990. Its totient is φ = 25605988.

The previous prime is 25605971. The next prime is 25605997. The reversal of 25605989 is 98950652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23203489 + 2402500 = 4817^2 + 1550^2 .

It is a cyclic number.

It is not a de Polignac number, because 25605989 - 2⁸ = 25605733 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25605919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12802994 + 12802995.

It is an arithmetic number, because the mean of its divisors is an integer number (12802995).

Almost surely, 2^25605989 is an apocalyptic number.

It is an amenable number.

25605989 is a deficient number, since it is larger than the sum of its proper divisors (1).

25605989 is an equidigital number, since it uses as much as digits as its factorization.

25605989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 194400, while the sum is 44.

The square root of 25605989 is about 5060.2360616872. The cubic root of 25605989 is about 294.7455010832.

The spelling of 25605989 in words is "twenty-five million, six hundred five thousand, nine hundred eighty-nine".