25081621 has 2 divisors, whose sum is σ = 25081622. Its totient is φ = 25081620.

The previous prime is 25081601. The next prime is 25081643. The reversal of 25081621 is 12618052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24502500 + 579121 = 4950^2 + 761^2 .

It is a cyclic number.

It is not a de Polignac number, because 25081621 - 2⁷ = 25081493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25081601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12540810 + 12540811.

It is an arithmetic number, because the mean of its divisors is an integer number (12540811).

Almost surely, 2^25081621 is an apocalyptic number.

It is an amenable number.

25081621 is a deficient number, since it is larger than the sum of its proper divisors (1).

25081621 is an equidigital number, since it uses as much as digits as its factorization.

25081621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 25081621 is about 5008.1554488654. The cubic root of 25081621 is about 292.7196431434.

Adding to 25081621 its reverse (12618052), we get a palindrome (37699673).

The spelling of 25081621 in words is "twenty-five million, eighty-one thousand, six hundred twenty-one".