18511225 has 12 divisors (see below), whose sum is σ = 24162640. Its totient is φ = 14029200.

The previous prime is 18511223. The next prime is 18511231. The reversal of 18511225 is 52211581.

It is not a de Polignac number, because 18511225 - 2¹ = 18511223 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a self number, because there is not a number n which added to its sum of digits gives 18511225.

It is not an unprimeable number, because it can be changed into a prime (18511223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19011 + ... + 19960.

Almost surely, 2^18511225 is an apocalyptic number.

It is an amenable number.

18511225 is a deficient number, since it is larger than the sum of its proper divisors (5651415).

18511225 is a wasteful number, since it uses less digits than its factorization.

18511225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39000 (or 38995 counting only the distinct ones).

The product of its digits is 800, while the sum is 25.

The square root of 18511225 is about 4302.4673153901. The cubic root of 18511225 is about 264.5321042169.

The spelling of 18511225 in words is "eighteen million, five hundred eleven thousand, two hundred twenty-five".