25205621 has 16 divisors (see below), whose sum is σ = 29774976. Its totient is φ = 20886336.

The previous prime is 25205603. The next prime is 25205629. The reversal of 25205621 is 12650252.

It is a cyclic number.

It is not a de Polignac number, because 25205621 - 2²² = 21011317 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25205629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79355 + ... + 79671.

It is an arithmetic number, because the mean of its divisors is an integer number (1860936).

Almost surely, 2^25205621 is an apocalyptic number.

It is an amenable number.

25205621 is a deficient number, since it is larger than the sum of its proper divisors (4569355).

25205621 is a wasteful number, since it uses less digits than its factorization.

25205621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 25205621 is about 5020.5199929888. The cubic root of 25205621 is about 293.2012385895.

Adding to 25205621 its reverse (12650252), we get a palindrome (37855873).

The spelling of 25205621 in words is "twenty-five million, two hundred five thousand, six hundred twenty-one".