18699820 has 24 divisors (see below), whose sum is σ = 40537728. Its totient is φ = 7238400.

The previous prime is 18699803. The next prime is 18699823. The reversal of 18699820 is 2899681.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (18699823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14461 + ... + 15700.

It is an arithmetic number, because the mean of its divisors is an integer number (1689072).

Almost surely, 2^18699820 is an apocalyptic number.

18699820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18699820 is an abundant number, since it is smaller than the sum of its proper divisors (21837908).

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

18699820 is a wasteful number, since it uses less digits than its factorization.

18699820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30201 (or 30199 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 18699820 is about 4324.3288496598. The cubic root of 18699820 is about 265.4274340833.

The spelling of 18699820 in words is "eighteen million, six hundred ninety-nine thousand, eight hundred twenty".