18686920 has 32 divisors (see below), whose sum is σ = 48052800. Its totient is φ = 6406848.

The previous prime is 18686911. The next prime is 18686947. The reversal of 18686920 is 2968681.

18686920 = T₄₉₇ + T₄₉₈ + ... + T₆₁₆.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33090 + ... + 33649.

It is an arithmetic number, because the mean of its divisors is an integer number (1501650).

Almost surely, 2^18686920 is an apocalyptic number.

18686920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18686920 is an abundant number, since it is smaller than the sum of its proper divisors (29365880).

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

18686920 is a wasteful number, since it uses less digits than its factorization.

18686920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66757 (or 66753 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 18686920 is about 4322.8370313950. The cubic root of 18686920 is about 265.3663853397.

The spelling of 18686920 in words is "eighteen million, six hundred eighty-six thousand, nine hundred twenty".