25117021 has 2 divisors, whose sum is σ = 25117022. Its totient is φ = 25117020.

The previous prime is 25117019. The next prime is 25117039. The reversal of 25117021 is 12071152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13793796 + 11323225 = 3714^2 + 3365^2 .

It is a cyclic number.

It is not a de Polignac number, because 25117021 - 2¹ = 25117019 is a prime.

Together with 25117019, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 25117021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25117061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12558510 + 12558511.

It is an arithmetic number, because the mean of its divisors is an integer number (12558511).

Almost surely, 2^25117021 is an apocalyptic number.

It is an amenable number.

25117021 is a deficient number, since it is larger than the sum of its proper divisors (1).

25117021 is an equidigital number, since it uses as much as digits as its factorization.

25117021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 25117021 is about 5011.6884380416. The cubic root of 25117021 is about 292.8572924619.

Adding to 25117021 its reverse (12071152), we get a palindrome (37188173).

The spelling of 25117021 in words is "twenty-five million, one hundred seventeen thousand, twenty-one".