20644234 has 8 divisors (see below), whose sum is σ = 33348420. Its totient is φ = 9528096.

The previous prime is 20644229. The next prime is 20644237. The reversal of 20644234 is 43244602.

20644234 is nontrivially palindromic in base 14.

It can be written as a sum of positive squares in 2 ways, for example, as 18533025 + 2111209 = 4305^2 + 1453^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 20644199 and 20644208.

It is not an unprimeable number, because it can be changed into a prime (20644237) 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, 396979 + ... + 397030.

Almost surely, 2^20644234 is an apocalyptic number.

20644234 is a deficient number, since it is larger than the sum of its proper divisors (12704186).

20644234 is a wasteful number, since it uses less digits than its factorization.

20644234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 794024.

The product of its (nonzero) digits is 4608, while the sum is 25.

The square root of 20644234 is about 4543.5926313876. The cubic root of 20644234 is about 274.3255494341.

Adding to 20644234 its reverse (43244602), we get a palindrome (63888836).

The spelling of 20644234 in words is "twenty million, six hundred forty-four thousand, two hundred thirty-four".