25205021 has 4 divisors (see below), whose sum is σ = 25318272. Its totient is φ = 25091772.

The previous prime is 25204979. The next prime is 25205023. The reversal of 25205021 is 12050252.

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-25205021 is a prime.

It is a super-2 number, since 2×25205021² = 1270586167220882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25205023) 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, 56291 + ... + 56736.

It is an arithmetic number, because the mean of its divisors is an integer number (6329568).

Almost surely, 2^25205021 is an apocalyptic number.

It is an amenable number.

25205021 is a deficient number, since it is larger than the sum of its proper divisors (113251).

25205021 is a wasteful number, since it uses less digits than its factorization.

25205021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113250.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 25205021 is about 5020.4602378666. The cubic root of 25205021 is about 293.1989120960.

Adding to 25205021 its reverse (12050252), we get a palindrome (37255273).

The spelling of 25205021 in words is "twenty-five million, two hundred five thousand, twenty-one".