20644806 has 32 divisors (see below), whose sum is σ = 50819328. Its totient is φ = 5444640.

The previous prime is 20644759. The next prime is 20644807. The reversal of 20644806 is 60844602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20644807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18360 + ... + 19451.

It is an arithmetic number, because the mean of its divisors is an integer number (1588104).

Almost surely, 2^20644806 is an apocalyptic number.

20644806 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20644806 is an abundant number, since it is smaller than the sum of its proper divisors (30174522).

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

20644806 is a wasteful number, since it uses less digits than its factorization.

20644806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37836.

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 20644806 is about 4543.6555767355. The cubic root of 20644806 is about 274.3280830352.

The spelling of 20644806 in words is "twenty million, six hundred forty-four thousand, eight hundred six".