25290821 has 2 divisors, whose sum is σ = 25290822. Its totient is φ = 25290820.

The previous prime is 25290803. The next prime is 25290827. The reversal of 25290821 is 12809252.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19936225 + 5354596 = 4465^2 + 2314^2 .

It is a cyclic number.

It is not a de Polignac number, because 25290821 - 2⁶ = 25290757 is a prime.

It is a plaindrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25290827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12645410 + 12645411.

It is an arithmetic number, because the mean of its divisors is an integer number (12645411).

Almost surely, 2^25290821 is an apocalyptic number.

It is an amenable number.

25290821 is a deficient number, since it is larger than the sum of its proper divisors (1).

25290821 is an equidigital number, since it uses as much as digits as its factorization.

25290821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 25290821 is about 5028.9980115327. The cubic root of 25290821 is about 293.5312265135.

The spelling of 25290821 in words is "twenty-five million, two hundred ninety thousand, eight hundred twenty-one".