18158225 has 12 divisors (see below), whose sum is σ = 22771980. Its totient is φ = 14361600.

The previous prime is 18158209. The next prime is 18158233. The reversal of 18158225 is 52285181.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 2421136 + 15737089 = 1556^2 + 3967^2 .

It is not a de Polignac number, because 18158225 - 2⁴ = 18158209 is a prime.

It is a super-2 number, since 2×18158225² = 659442270301250, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18158191 and 18158200.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1856 + ... + 6305.

It is an arithmetic number, because the mean of its divisors is an integer number (1897665).

Almost surely, 2^18158225 is an apocalyptic number.

It is an amenable number.

18158225 is a deficient number, since it is larger than the sum of its proper divisors (4613755).

18158225 is an equidigital number, since it uses as much as digits as its factorization.

18158225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8260 (or 8255 counting only the distinct ones).

The product of its digits is 6400, while the sum is 32.

The square root of 18158225 is about 4261.2468832491. The cubic root of 18158225 is about 262.8398018170.

The spelling of 18158225 in words is "eighteen million, one hundred fifty-eight thousand, two hundred twenty-five".