18381525 has 12 divisors (see below), whose sum is σ = 30390912. Its totient is φ = 9803440.

The previous prime is 18381521. The next prime is 18381547. The reversal of 18381525 is 52518381.

It is a happy number.

It is not a de Polignac number, because 18381525 - 2² = 18381521 is a prime.

It is a super-2 number, since 2×18381525² = 675760922651250, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18381521) 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, 122469 + ... + 122618.

It is an arithmetic number, because the mean of its divisors is an integer number (2532576).

Almost surely, 2^18381525 is an apocalyptic number.

18381525 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18381525 is a deficient number, since it is larger than the sum of its proper divisors (12009387).

18381525 is a wasteful number, since it uses less digits than its factorization.

18381525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245100 (or 245095 counting only the distinct ones).

The product of its digits is 9600, while the sum is 33.

The square root of 18381525 is about 4287.3680737721. The cubic root of 18381525 is about 263.9128356642.

The spelling of 18381525 in words is "eighteen million, three hundred eighty-one thousand, five hundred twenty-five".