25221997 has 2 divisors, whose sum is σ = 25221998. Its totient is φ = 25221996.

The previous prime is 25221991. The next prime is 25222013. The reversal of 25221997 is 79912252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24940036 + 281961 = 4994^2 + 531^2 .

It is a cyclic number.

It is not a de Polignac number, because 25221997 - 2²³ = 16833389 is a prime.

It is a super-2 number, since 2×25221997² = 1272298265336018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25221991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12610998 + 12610999.

It is an arithmetic number, because the mean of its divisors is an integer number (12610999).

Almost surely, 2^25221997 is an apocalyptic number.

It is an amenable number.

25221997 is a deficient number, since it is larger than the sum of its proper divisors (1).

25221997 is an equidigital number, since it uses as much as digits as its factorization.

25221997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22680, while the sum is 37.

The square root of 25221997 is about 5022.1506349372. The cubic root of 25221997 is about 293.2647221015.

The spelling of 25221997 in words is "twenty-five million, two hundred twenty-one thousand, nine hundred ninety-seven".