18225531 has 12 divisors (see below), whose sum is σ = 26504400. Its totient is φ = 12067920.

The previous prime is 18225523. The next prime is 18225539. The reversal of 18225531 is 13552281.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18225523) and next prime (18225539).

It is not a de Polignac number, because 18225531 - 2³ = 18225523 is a prime.

It is a super-2 number, since 2×18225531² = 664339960463922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18225495 and 18225504.

It is not an unprimeable number, because it can be changed into a prime (18225539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5455 + ... + 8136.

It is an arithmetic number, because the mean of its divisors is an integer number (2208700).

Almost surely, 2^18225531 is an apocalyptic number.

18225531 is a deficient number, since it is larger than the sum of its proper divisors (8278869).

18225531 is a wasteful number, since it uses less digits than its factorization.

18225531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13746 (or 13743 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 18225531 is about 4269.1370322350. The cubic root of 18225531 is about 263.1641522224.

The spelling of 18225531 in words is "eighteen million, two hundred twenty-five thousand, five hundred thirty-one".