215240225 has 6 divisors (see below), whose sum is σ = 266897910. Its totient is φ = 172192160.

The previous prime is 215240203. The next prime is 215240251. The reversal of 215240225 is 522042512.

It can be written as a sum of positive squares in 3 ways, for example, as 2430481 + 212809744 = 1559^2 + 14588^2 .

It is not a de Polignac number, because 215240225 - 2²² = 211045921 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 215240225.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4304780 + ... + 4304829.

It is an arithmetic number, because the mean of its divisors is an integer number (44482985).

Almost surely, 2^215240225 is an apocalyptic number.

215240225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

215240225 is a deficient number, since it is larger than the sum of its proper divisors (51657685).

215240225 is an equidigital number, since it uses as much as digits as its factorization.

215240225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8609619 (or 8609614 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 215240225 is about 14671.0676162303. The cubic root of 215240225 is about 599.2956781711.

Adding to 215240225 its reverse (522042512), we get a palindrome (737282737).

The spelling of 215240225 in words is "two hundred fifteen million, two hundred forty thousand, two hundred twenty-five".