25515121 has 2 divisors, whose sum is σ = 25515122. Its totient is φ = 25515120.

The previous prime is 25515109. The next prime is 25515167. The reversal of 25515121 is 12151552.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25200400 + 314721 = 5020^2 + 561^2 .

It is a cyclic number.

It is not a de Polignac number, because 25515121 - 2¹⁷ = 25384049 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25515092 and 25515101.

It is not a weakly prime, because it can be changed into another prime (25515221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12757560 + 12757561.

It is an arithmetic number, because the mean of its divisors is an integer number (12757561).

Almost surely, 2^25515121 is an apocalyptic number.

It is an amenable number.

25515121 is a deficient number, since it is larger than the sum of its proper divisors (1).

25515121 is an equidigital number, since it uses as much as digits as its factorization.

25515121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 500, while the sum is 22.

The square root of 25515121 is about 5051.2494493937. The cubic root of 25515121 is about 294.3964332884.

Adding to 25515121 its reverse (12151552), we get a palindrome (37666673).

It can be divided in two parts, 255 and 15121, that added together give a square (15376 = 124²).

The spelling of 25515121 in words is "twenty-five million, five hundred fifteen thousand, one hundred twenty-one".