18681420 has 48 divisors (see below), whose sum is σ = 52496640. Its totient is φ = 4963776.

The previous prime is 18681373. The next prime is 18681431. The reversal of 18681420 is 2418681.

It is a Harshad number since it is a multiple of its sum of digits (30).

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 15 ways as a sum of consecutive naturals, for example, 29871 + ... + 30489.

It is an arithmetic number, because the mean of its divisors is an integer number (1093680).

Almost surely, 2^18681420 is an apocalyptic number.

18681420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18681420 is an abundant number, since it is smaller than the sum of its proper divisors (33815220).

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

18681420 is a wasteful number, since it uses less digits than its factorization.

18681420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1134 (or 1132 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 18681420 is about 4322.2008282818. The cubic root of 18681420 is about 265.3403482625.

The spelling of 18681420 in words is "eighteen million, six hundred eighty-one thousand, four hundred twenty".