18921473 has 8 divisors (see below), whose sum is σ = 19960320. Its totient is φ = 17886960.

The previous prime is 18921457. The next prime is 18921503. The reversal of 18921473 is 37412981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18921473 - 2⁴ = 18921457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18921443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12128 + ... + 13598.

It is an arithmetic number, because the mean of its divisors is an integer number (2495040).

Almost surely, 2^18921473 is an apocalyptic number.

It is an amenable number.

18921473 is a deficient number, since it is larger than the sum of its proper divisors (1038847).

18921473 is a wasteful number, since it uses less digits than its factorization.

18921473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2167.

The product of its digits is 12096, while the sum is 35.

The square root of 18921473 is about 4349.8819524212. The cubic root of 18921473 is about 266.4720404522.

The spelling of 18921473 in words is "eighteen million, nine hundred twenty-one thousand, four hundred seventy-three".