215800225 has 6 divisors (see below), whose sum is σ = 267592310. Its totient is φ = 172640160.

The previous prime is 215800219. The next prime is 215800231. The reversal of 215800225 is 522008512.

It is an interprime number because it is at equal distance from previous prime (215800219) and next prime (215800231).

It can be written as a sum of positive squares in 3 ways, for example, as 327184 + 215473041 = 572^2 + 14679^2 .

It is not a de Polignac number, because 215800225 - 2³ = 215800217 is a prime.

It is a super-2 number, since 2×215800225² = 93139474220101250, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 8632009 = 215800225 / (2 + 1 + 5 + 8 + 0 + 0 + 2 + 2 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 215800225.

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, 4315980 + ... + 4316029.

Almost surely, 2^215800225 is an apocalyptic number.

215800225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

215800225 is a deficient number, since it is larger than the sum of its proper divisors (51792085).

215800225 is an equidigital number, since it uses as much as digits as its factorization.

215800225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8632019 (or 8632014 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 215800225 is about 14690.1404009628. The cubic root of 215800225 is about 599.8149660914.

Adding to 215800225 its reverse (522008512), we get a palindrome (737808737).

The spelling of 215800225 in words is "two hundred fifteen million, eight hundred thousand, two hundred twenty-five".