20644433 has 4 divisors (see below), whose sum is σ = 21356340. Its totient is φ = 19932528.

The previous prime is 20644399. The next prime is 20644447. The reversal of 20644433 is 33444602.

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 14922769 + 5721664 = 3863^2 + 2392^2 .

It is a cyclic number.

It is not a de Polignac number, because 20644433 - 2⁶ = 20644369 is a prime.

It is a super-2 number, since 2×20644433² = 852385227782978, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20644453) 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, 355910 + ... + 355967.

It is an arithmetic number, because the mean of its divisors is an integer number (5339085).

Almost surely, 2^20644433 is an apocalyptic number.

It is an amenable number.

20644433 is a deficient number, since it is larger than the sum of its proper divisors (711907).

20644433 is an equidigital number, since it uses as much as digits as its factorization.

20644433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 711906.

The product of its (nonzero) digits is 6912, while the sum is 26.

The square root of 20644433 is about 4543.6145303051. The cubic root of 20644433 is about 274.3264308845.

The spelling of 20644433 in words is "twenty million, six hundred forty-four thousand, four hundred thirty-three".