21418833 has 12 divisors (see below), whose sum is σ = 30110640. Its totient is φ = 13505616.

The previous prime is 21418823. The next prime is 21418841. The reversal of 21418833 is 33881412.

It is not a de Polignac number, because 21418833 - 2⁵ = 21418801 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21418833.

It is not an unprimeable number, because it can be changed into a prime (21418823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34635 + ... + 35247.

It is an arithmetic number, because the mean of its divisors is an integer number (2509220).

Almost surely, 2^21418833 is an apocalyptic number.

It is an amenable number.

21418833 is a deficient number, since it is larger than the sum of its proper divisors (8691807).

21418833 is an frugal number, since it uses more digits than its factorization.

21418833 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248 (or 635 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 21418833 is about 4628.0485088210. The cubic root of 21418833 is about 277.7145293450.

The spelling of 21418833 in words is "twenty-one million, four hundred eighteen thousand, eight hundred thirty-three".