16418921 has 4 divisors (see below), whose sum is σ = 16578432. Its totient is φ = 16259412.

The previous prime is 16418917. The next prime is 16418929. The reversal of 16418921 is 12981461.

16418921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12981461 = 41 ⋅316621.

It is a cyclic number.

It is not a de Polignac number, because 16418921 - 2² = 16418917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16418929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79601 + ... + 79806.

It is an arithmetic number, because the mean of its divisors is an integer number (4144608).

Almost surely, 2^16418921 is an apocalyptic number.

It is an amenable number.

16418921 is a deficient number, since it is larger than the sum of its proper divisors (159511).

16418921 is a wasteful number, since it uses less digits than its factorization.

16418921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159510.

The product of its digits is 3456, while the sum is 32.

The square root of 16418921 is about 4052.0267768118. The cubic root of 16418921 is about 254.1644882850.

The spelling of 16418921 in words is "sixteen million, four hundred eighteen thousand, nine hundred twenty-one".