18261225 has 36 divisors (see below), whose sum is σ = 32937996. Its totient is φ = 9671040.

The previous prime is 18261211. The next prime is 18261227. The reversal of 18261225 is 52216281.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 36864 + 18224361 = 192^2 + 4269^2 .

It is not a de Polignac number, because 18261225 - 2⁴ = 18261209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18261227) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 62179 + ... + 62471.

Almost surely, 2^18261225 is an apocalyptic number.

18261225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18261225 is a deficient number, since it is larger than the sum of its proper divisors (14676771).

18261225 is a wasteful number, since it uses less digits than its factorization.

18261225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586 (or 578 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 18261225 is about 4273.3154575809. The cubic root of 18261225 is about 263.3358391401.

The spelling of 18261225 in words is "eighteen million, two hundred sixty-one thousand, two hundred twenty-five".