20218733 has 4 divisors (see below), whose sum is σ = 20232828. Its totient is φ = 20204640.

The previous prime is 20218721. The next prime is 20218787. The reversal of 20218733 is 33781202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14845609 + 5373124 = 3853^2 + 2318^2 .

It is a cyclic number.

It is not a de Polignac number, because 20218733 - 2⁶ = 20218669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20218703) 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, 4616 + ... + 7857.

It is an arithmetic number, because the mean of its divisors is an integer number (5058207).

Almost surely, 2^20218733 is an apocalyptic number.

It is an amenable number.

20218733 is a deficient number, since it is larger than the sum of its proper divisors (14095).

20218733 is a wasteful number, since it uses less digits than its factorization.

20218733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14094.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 20218733 is about 4496.5245468028. The cubic root of 20218733 is about 272.4277304634.

Adding to 20218733 its reverse (33781202), we get a palindrome (53999935).

The spelling of 20218733 in words is "twenty million, two hundred eighteen thousand, seven hundred thirty-three".