25215231 has 4 divisors (see below), whose sum is σ = 33620312. Its totient is φ = 16810152.

The previous prime is 25215221. The next prime is 25215251. The reversal of 25215231 is 13251252.

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

It is not a de Polignac number, because 25215231 - 2⁷ = 25215103 is a prime.

It is a super-2 number, since 2×25215231² = 1271615748766722, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 25215198 and 25215207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25215221) 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, 4202536 + ... + 4202541.

It is an arithmetic number, because the mean of its divisors is an integer number (8405078).

Almost surely, 2^25215231 is an apocalyptic number.

25215231 is a deficient number, since it is larger than the sum of its proper divisors (8405081).

25215231 is an equidigital number, since it uses as much as digits as its factorization.

25215231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8405080.

The product of its digits is 600, while the sum is 21.

The square root of 25215231 is about 5021.4769739590. The cubic root of 25215231 is about 293.2384962299.

Adding to 25215231 its reverse (13251252), we get a palindrome (38466483).

The spelling of 25215231 in words is "twenty-five million, two hundred fifteen thousand, two hundred thirty-one".