18715225 has 6 divisors (see below), whose sum is σ = 23206910. Its totient is φ = 14972160.

The previous prime is 18715223. The next prime is 18715231. The reversal of 18715225 is 52251781.

It can be written as a sum of positive squares in 3 ways, for example, as 26896 + 18688329 = 164^2 + 4323^2 .

It is not a de Polignac number, because 18715225 - 2¹ = 18715223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18715223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 374280 + ... + 374329.

Almost surely, 2^18715225 is an apocalyptic number.

It is an amenable number.

18715225 is a deficient number, since it is larger than the sum of its proper divisors (4491685).

18715225 is an equidigital number, since it uses as much as digits as its factorization.

18715225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748619 (or 748614 counting only the distinct ones).

The product of its digits is 5600, while the sum is 31.

The square root of 18715225 is about 4326.1096842313. The cubic root of 18715225 is about 265.5003008687.

The spelling of 18715225 in words is "eighteen million, seven hundred fifteen thousand, two hundred twenty-five".