25630421 has 2 divisors, whose sum is σ = 25630422. Its totient is φ = 25630420.

The previous prime is 25630399. The next prime is 25630427. The reversal of 25630421 is 12403652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22944100 + 2686321 = 4790^2 + 1639^2 .

It is a cyclic number.

It is not a de Polignac number, because 25630421 - 2⁶ = 25630357 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_1602806 and since 25630421 and 1602806 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25630427) 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, 12815210 + 12815211.

It is an arithmetic number, because the mean of its divisors is an integer number (12815211).

Almost surely, 2^25630421 is an apocalyptic number.

It is an amenable number.

25630421 is a deficient number, since it is larger than the sum of its proper divisors (1).

25630421 is an equidigital number, since it uses as much as digits as its factorization.

25630421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 25630421 is about 5062.6496027278. The cubic root of 25630421 is about 294.8392152652.

The spelling of 25630421 in words is "twenty-five million, six hundred thirty thousand, four hundred twenty-one".