25221617 has 2 divisors, whose sum is σ = 25221618. Its totient is φ = 25221616.

The previous prime is 25221613. The next prime is 25221653. The reversal of 25221617 is 71612252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24760576 + 461041 = 4976^2 + 679^2 .

It is a cyclic number.

It is not a de Polignac number, because 25221617 - 2² = 25221613 is a prime.

It is a super-2 number, since 2×25221617² = 1272259928189378, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25221611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12610808 + 12610809.

It is an arithmetic number, because the mean of its divisors is an integer number (12610809).

Almost surely, 2^25221617 is an apocalyptic number.

It is an amenable number.

25221617 is a deficient number, since it is larger than the sum of its proper divisors (1).

25221617 is an equidigital number, since it uses as much as digits as its factorization.

25221617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 26.

The square root of 25221617 is about 5022.1128023970. The cubic root of 25221617 is about 293.2632492977.

Adding to 25221617 its reverse (71612252), we get a palindrome (96833869).

The spelling of 25221617 in words is "twenty-five million, two hundred twenty-one thousand, six hundred seventeen".