20742233 has 4 divisors (see below), whose sum is σ = 20751588. Its totient is φ = 20732880.

The previous prime is 20742229. The next prime is 20742247. The reversal of 20742233 is 33224702.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 3211264 + 17530969 = 1792^2 + 4187^2 .

It is a cyclic number.

It is not a de Polignac number, because 20742233 - 2² = 20742229 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20742199 and 20742208.

It is not an unprimeable number, because it can be changed into a prime (20742203) 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, 743 + ... + 6483.

It is an arithmetic number, because the mean of its divisors is an integer number (5187897).

Almost surely, 2^20742233 is an apocalyptic number.

It is an amenable number.

20742233 is a deficient number, since it is larger than the sum of its proper divisors (9355).

20742233 is an equidigital number, since it uses as much as digits as its factorization.

20742233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9354.

The product of its (nonzero) digits is 2016, while the sum is 23.

The square root of 20742233 is about 4554.3641707707. The cubic root of 20742233 is about 274.7589424763.

Adding to 20742233 its reverse (33224702), we get a palindrome (53966935).

The spelling of 20742233 in words is "twenty million, seven hundred forty-two thousand, two hundred thirty-three".