20644051 has 4 divisors (see below), whose sum is σ = 21730600. Its totient is φ = 19557504.

The previous prime is 20644049. The next prime is 20644079. The reversal of 20644051 is 15044602.

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

It is a cyclic number.

It is not a de Polignac number, because 20644051 - 2¹ = 20644049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20644081) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 543246 + ... + 543283.

It is an arithmetic number, because the mean of its divisors is an integer number (5432650).

Almost surely, 2^20644051 is an apocalyptic number.

20644051 is a deficient number, since it is larger than the sum of its proper divisors (1086549).

20644051 is a wasteful number, since it uses less digits than its factorization.

20644051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1086548.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 20644051 is about 4543.5724930940. The cubic root of 20644051 is about 274.3247388490.

Adding to 20644051 its reverse (15044602), we get a palindrome (35688653).

The spelling of 20644051 in words is "twenty million, six hundred forty-four thousand, fifty-one".