18664425 has 60 divisors (see below), whose sum is σ = 37284940. Its totient is φ = 9175680.

The previous prime is 18664417. The next prime is 18664433. The reversal of 18664425 is 52446681.

18664425 is a `hidden beast` number, since 1 + 8 + 6 + 644 + 2 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (18664417) and next prime (18664433).

It can be written as a sum of positive squares in 6 ways, for example, as 4981824 + 13682601 = 2232^2 + 3699^2 .

It is not a de Polignac number, because 18664425 - 2³ = 18664417 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18664425.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 25971 + ... + 26679.

Almost surely, 2^18664425 is an apocalyptic number.

18664425 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18664425 is a deficient number, since it is larger than the sum of its proper divisors (18620515).

18664425 is a wasteful number, since it uses less digits than its factorization.

18664425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744 (or 730 counting only the distinct ones).

The product of its digits is 46080, while the sum is 36.

The square root of 18664425 is about 4320.2343686425. The cubic root of 18664425 is about 265.2598613872.

The spelling of 18664425 in words is "eighteen million, six hundred sixty-four thousand, four hundred twenty-five".