20428806 has 8 divisors (see below), whose sum is σ = 40857624. Its totient is φ = 6809600.

The previous prime is 20428801. The next prime is 20428817. The reversal of 20428806 is 60882402.

It is a happy number.

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

20428806 is an admirable number.

It is a super-2 number, since 2×20428806² = 834672229171272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20428801) 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, 1702395 + ... + 1702406.

It is an arithmetic number, because the mean of its divisors is an integer number (5107203).

Almost surely, 2^20428806 is an apocalyptic number.

20428806 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20428806 is a wasteful number, since it uses less digits than its factorization.

20428806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3404806.

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 20428806 is about 4519.8236691269. The cubic root of 20428806 is about 273.3679911767.

The spelling of 20428806 in words is "twenty million, four hundred twenty-eight thousand, eight hundred six".