18421980 has 24 divisors (see below), whose sum is σ = 51581712. Its totient is φ = 4912512.

The previous prime is 18421973. The next prime is 18421987. The reversal of 18421980 is 8912481.

It is an interprime number because it is at equal distance from previous prime (18421973) and next prime (18421987).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18421987) by changing a digit.

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, 153457 + ... + 153576.

It is an arithmetic number, because the mean of its divisors is an integer number (2149238).

Almost surely, 2^18421980 is an apocalyptic number.

18421980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18421980 is an abundant number, since it is smaller than the sum of its proper divisors (33159732).

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

18421980 is a wasteful number, since it uses less digits than its factorization.

18421980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307045 (or 307043 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 33.

The square root of 18421980 is about 4292.0834101867. The cubic root of 18421980 is about 264.1063047551.

The spelling of 18421980 in words is "eighteen million, four hundred twenty-one thousand, nine hundred eighty".