25917421 has 2 divisors, whose sum is σ = 25917422. Its totient is φ = 25917420.

The previous prime is 25917383. The next prime is 25917431. The reversal of 25917421 is 12471952.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25704900 + 212521 = 5070^2 + 461^2 .

It is a cyclic number.

It is not a de Polignac number, because 25917421 - 2¹³ = 25909229 is a prime.

It is a super-2 number, since 2×25917421² = 1343425422582482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25917431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12958710 + 12958711.

It is an arithmetic number, because the mean of its divisors is an integer number (12958711).

Almost surely, 2^25917421 is an apocalyptic number.

It is an amenable number.

25917421 is a deficient number, since it is larger than the sum of its proper divisors (1).

25917421 is an equidigital number, since it uses as much as digits as its factorization.

25917421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 31.

The square root of 25917421 is about 5090.9155365219. The cubic root of 25917421 is about 295.9356332223.

The spelling of 25917421 in words is "twenty-five million, nine hundred seventeen thousand, four hundred twenty-one".