25015324921 has 2 divisors, whose sum is σ = 25015324922. Its totient is φ = 25015324920.

The previous prime is 25015324897. The next prime is 25015324927. The reversal of 25015324921 is 12942351052.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19870849296 + 5144475625 = 140964^2 + 71725^2 .

It is a cyclic number.

It is not a de Polignac number, because 25015324921 - 2²³ = 25006936313 is a prime.

It is a super-3 number, since 3×25015324921³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (25015324927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12507662460 + 12507662461.

It is an arithmetic number, because the mean of its divisors is an integer number (12507662461).

Almost surely, 2^25015324921 is an apocalyptic number.

It is an amenable number.

25015324921 is a deficient number, since it is larger than the sum of its proper divisors (1).

25015324921 is an equidigital number, since it uses as much as digits as its factorization.

25015324921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 34.

Adding to 25015324921 its reverse (12942351052), we get a palindrome (37957675973).

The spelling of 25015324921 in words is "twenty-five billion, fifteen million, three hundred twenty-four thousand, nine hundred twenty-one".