20646638 has 8 divisors (see below), whose sum is σ = 31000320. Its totient is φ = 10313200.

The previous prime is 20646631. The next prime is 20646667. The reversal of 20646638 is 83664602.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20646598 and 20646607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20646631) 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, 2183 + ... + 6786.

It is an arithmetic number, because the mean of its divisors is an integer number (3875040).

Almost surely, 2^20646638 is an apocalyptic number.

20646638 is a deficient number, since it is larger than the sum of its proper divisors (10353682).

20646638 is a wasteful number, since it uses less digits than its factorization.

20646638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10122.

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 20646638 is about 4543.8571720511. The cubic root of 20646638 is about 274.3361973309.

The spelling of 20646638 in words is "twenty million, six hundred forty-six thousand, six hundred thirty-eight".