18213425 has 6 divisors (see below), whose sum is σ = 22584678. Its totient is φ = 14570720.

The previous prime is 18213383. The next prime is 18213449. The reversal of 18213425 is 52431281.

It can be written as a sum of positive squares in 3 ways, for example, as 303601 + 17909824 = 551^2 + 4232^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18213425 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18213394 and 18213403.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 364244 + ... + 364293.

It is an arithmetic number, because the mean of its divisors is an integer number (3764113).

Almost surely, 2^18213425 is an apocalyptic number.

It is an amenable number.

18213425 is a deficient number, since it is larger than the sum of its proper divisors (4371253).

18213425 is an equidigital number, since it uses as much as digits as its factorization.

18213425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728547 (or 728542 counting only the distinct ones).

The product of its digits is 1920, while the sum is 26.

The square root of 18213425 is about 4267.7189457601. The cubic root of 18213425 is about 263.1058718743.

The spelling of 18213425 in words is "eighteen million, two hundred thirteen thousand, four hundred twenty-five".