25115621 has 4 divisors (see below), whose sum is σ = 25260972. Its totient is φ = 24970272.

The previous prime is 25115603. The next prime is 25115633. The reversal of 25115621 is 12651152.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24453025 + 662596 = 4945^2 + 814^2 .

It is a cyclic number.

It is not a de Polignac number, because 25115621 - 2¹⁴ = 25099237 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25115641) 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, 72416 + ... + 72761.

It is an arithmetic number, because the mean of its divisors is an integer number (6315243).

Almost surely, 2^25115621 is an apocalyptic number.

It is an amenable number.

25115621 is a deficient number, since it is larger than the sum of its proper divisors (145351).

25115621 is a wasteful number, since it uses less digits than its factorization.

25115621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145350.

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

The square root of 25115621 is about 5011.5487626082. The cubic root of 25115621 is about 292.8518511607.

Adding to 25115621 its reverse (12651152), we get a palindrome (37766773).

The spelling of 25115621 in words is "twenty-five million, one hundred fifteen thousand, six hundred twenty-one".