25615121 has 4 divisors (see below), whose sum is σ = 29274432. Its totient is φ = 21955812.

The previous prime is 25615099. The next prime is 25615127. The reversal of 25615121 is 12151652.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25615121 is a prime.

It is a super-2 number, since 2×25615121² = 1312268847689282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25615127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1829645 + ... + 1829658.

It is an arithmetic number, because the mean of its divisors is an integer number (7318608).

Almost surely, 2^25615121 is an apocalyptic number.

It is an amenable number.

25615121 is a deficient number, since it is larger than the sum of its proper divisors (3659311).

25615121 is an equidigital number, since it uses as much as digits as its factorization.

25615121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3659310.

The product of its digits is 600, while the sum is 23.

The square root of 25615121 is about 5061.1383106965. The cubic root of 25615121 is about 294.7805358037.

Adding to 25615121 its reverse (12151652), we get a palindrome (37766773).

It can be divided in two parts, 2561 and 5121, that multiplied together give a triangular number (13114881 = T₅₁₂₁).

The spelling of 25615121 in words is "twenty-five million, six hundred fifteen thousand, one hundred twenty-one".