20664438 has 32 divisors (see below), whose sum is σ = 43929600. Its totient is φ = 6461856.

The previous prime is 20664437. The next prime is 20664461. The reversal of 20664438 is 83446602.

It is a junction number, because it is equal to n+sod(n) for n = 20664399 and 20664408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20664431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11595 + ... + 13257.

It is an arithmetic number, because the mean of its divisors is an integer number (1372800).

Almost surely, 2^20664438 is an apocalyptic number.

20664438 is an abundant number, since it is smaller than the sum of its proper divisors (23265162).

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

20664438 is a wasteful number, since it uses less digits than its factorization.

20664438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1796.

The product of its (nonzero) digits is 27648, while the sum is 33.

The square root of 20664438 is about 4545.8154384005. The cubic root of 20664438 is about 274.4150121268.

The spelling of 20664438 in words is "twenty million, six hundred sixty-four thousand, four hundred thirty-eight".