25959821 has 2 divisors, whose sum is σ = 25959822. Its totient is φ = 25959820.

The previous prime is 25959781. The next prime is 25959853. The reversal of 25959821 is 12895952.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18369796 + 7590025 = 4286^2 + 2755^2 .

It is a cyclic number.

It is not a de Polignac number, because 25959821 - 2¹⁸ = 25697677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25959881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12979910 + 12979911.

It is an arithmetic number, because the mean of its divisors is an integer number (12979911).

Almost surely, 2^25959821 is an apocalyptic number.

It is an amenable number.

25959821 is a deficient number, since it is larger than the sum of its proper divisors (1).

25959821 is an equidigital number, since it uses as much as digits as its factorization.

25959821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64800, while the sum is 41.

The square root of 25959821 is about 5095.0781152010. The cubic root of 25959821 is about 296.0969254350.

The spelling of 25959821 in words is "twenty-five million, nine hundred fifty-nine thousand, eight hundred twenty-one".