20684406 has 32 divisors (see below), whose sum is σ = 44345088. Its totient is φ = 6415200.

The previous prime is 20684387. The next prime is 20684413. The reversal of 20684406 is 60448602.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3081 + ... + 7131.

It is an arithmetic number, because the mean of its divisors is an integer number (1385784).

Almost surely, 2^20684406 is an apocalyptic number.

20684406 is an abundant number, since it is smaller than the sum of its proper divisors (23660682).

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

20684406 is a wasteful number, since it uses less digits than its factorization.

20684406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4116.

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

The square root of 20684406 is about 4548.0112137065. The cubic root of 20684406 is about 274.5033725419.

The spelling of 20684406 in words is "twenty million, six hundred eighty-four thousand, four hundred six".