18721850 has 48 divisors (see below), whose sum is σ = 40176000. Its totient is φ = 6358080.

The previous prime is 18721847. The next prime is 18721853. The reversal of 18721850 is 5812781.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18721847) and next prime (18721853).

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (18721853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51971 + ... + 52329.

It is an arithmetic number, because the mean of its divisors is an integer number (837000).

Almost surely, 2^18721850 is an apocalyptic number.

18721850 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18721850 is an abundant number, since it is smaller than the sum of its proper divisors (21454150).

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

18721850 is a wasteful number, since it uses less digits than its factorization.

18721850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527 (or 522 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 18721850 is about 4326.8753159757. The cubic root of 18721850 is about 265.5316253115.

The spelling of 18721850 in words is "eighteen million, seven hundred twenty-one thousand, eight hundred fifty".