25515220 has 24 divisors (see below), whose sum is σ = 54087264. Its totient is φ = 10109856.

The previous prime is 25515209. The next prime is 25515221. The reversal of 25515220 is 2251552.

It is a junction number, because it is equal to n+sod(n) for n = 25515191 and 25515200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25515221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3822 + ... + 8101.

It is an arithmetic number, because the mean of its divisors is an integer number (2253636).

Almost surely, 2^25515220 is an apocalyptic number.

25515220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25515220 is an abundant number, since it is smaller than the sum of its proper divisors (28572044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25515220 is a wasteful number, since it uses less digits than its factorization.

25515220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12039 (or 12037 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 25515220 is about 5051.2592489398. The cubic root of 25515220 is about 294.3968140457.

Adding to 25515220 its reverse (2251552), we get a palindrome (27766772).

The spelling of 25515220 in words is "twenty-five million, five hundred fifteen thousand, two hundred twenty".