20644266 has 16 divisors (see below), whose sum is σ = 41468544. Its totient is φ = 6851424.

The previous prime is 20644237. The next prime is 20644303. The reversal of 20644266 is 66244602.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5986 + ... + 8781.

It is an arithmetic number, because the mean of its divisors is an integer number (2591784).

Almost surely, 2^20644266 is an apocalyptic number.

20644266 is an abundant number, since it is smaller than the sum of its proper divisors (20824278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20644266 is a wasteful number, since it uses less digits than its factorization.

20644266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15005.

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 20644266 is about 4543.5961528287. The cubic root of 20644266 is about 274.3256911752.

Adding to 20644266 its reverse (66244602), we get a palindrome (86888868).

It can be divided in two parts, 20644 and 266, that added together give a triangular number (20910 = T₂₀₄).

The spelling of 20644266 in words is "twenty million, six hundred forty-four thousand, two hundred sixty-six".