18671920 has 40 divisors (see below), whose sum is σ = 44818560. Its totient is φ = 7226880.

The previous prime is 18671909. The next prime is 18671923. The reversal of 18671920 is 2917681.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (18671923) 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, 1285 + ... + 6244.

It is an arithmetic number, because the mean of its divisors is an integer number (1120464).

Almost surely, 2^18671920 is an apocalyptic number.

18671920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18671920 is an abundant number, since it is smaller than the sum of its proper divisors (26146640).

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

18671920 is a wasteful number, since it uses less digits than its factorization.

18671920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7573 (or 7567 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 18671920 is about 4321.1017113695. The cubic root of 18671920 is about 265.2953630898.

It can be divided in two parts, 18671 and 920, that added together give a palindrome (19591).

The spelling of 18671920 in words is "eighteen million, six hundred seventy-one thousand, nine hundred twenty".