25007921 has 2 divisors, whose sum is σ = 25007922. Its totient is φ = 25007920.

The previous prime is 25007869. The next prime is 25007929. The reversal of 25007921 is 12970052.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25000000 + 7921 = 5000^2 + 89^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25007921 is a prime.

It is a super-2 number, since 2×25007921² = 1250792225484482, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (25007929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12503960 + 12503961.

It is an arithmetic number, because the mean of its divisors is an integer number (12503961).

Almost surely, 2^25007921 is an apocalyptic number.

It is an amenable number.

25007921 is a deficient number, since it is larger than the sum of its proper divisors (1).

25007921 is an equidigital number, since it uses as much as digits as its factorization.

25007921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 25007921 is about 5000.7920372677. The cubic root of 25007921 is about 292.4326520864.

Adding to 25007921 its reverse (12970052), we get a palindrome (37977973).

It can be divided in two parts, 2500 and 7921, that multiplied together give a square (19802500 = 4450²).

The spelling of 25007921 in words is "twenty-five million, seven thousand, nine hundred twenty-one".