20644085 has 48 divisors (see below), whose sum is σ = 32711040. Its totient is φ = 12136320.

The previous prime is 20644081. The next prime is 20644093. The reversal of 20644085 is 58044602.

It is not a de Polignac number, because 20644085 - 2² = 20644081 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Curzon number.

It is a congruent number.

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

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 480074 + ... + 480116.

It is an arithmetic number, because the mean of its divisors is an integer number (681480).

Almost surely, 2^20644085 is an apocalyptic number.

It is an amenable number.

20644085 is a deficient number, since it is larger than the sum of its proper divisors (12066955).

20644085 is a wasteful number, since it uses less digits than its factorization.

20644085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 20644085 is about 4543.5762346416. The cubic root of 20644085 is about 274.3248894499.

Adding to 20644085 its reverse (58044602), we get a palindrome (78688687).

The spelling of 20644085 in words is "twenty million, six hundred forty-four thousand, eighty-five".