18195820 has 12 divisors (see below), whose sum is σ = 38211264. Its totient is φ = 7278320.

The previous prime is 18195811. The next prime is 18195839. The reversal of 18195820 is 2859181.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 454876 + ... + 454915.

It is an arithmetic number, because the mean of its divisors is an integer number (3184272).

Almost surely, 2^18195820 is an apocalyptic number.

18195820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18195820 is an abundant number, since it is smaller than the sum of its proper divisors (20015444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18195820 is a wasteful number, since it uses less digits than its factorization.

18195820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909800 (or 909798 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 18195820 is about 4265.6558698517. The cubic root of 18195820 is about 263.0210722994.

The spelling of 18195820 in words is "eighteen million, one hundred ninety-five thousand, eight hundred twenty".