20428816 has 20 divisors (see below), whose sum is σ = 39703932. Its totient is φ = 10182656.

The previous prime is 20428801. The next prime is 20428817. The reversal of 20428816 is 61882402.

It can be written as a sum of positive squares in 2 ways, for example, as 2822400 + 17606416 = 1680^2 + 4196^2 .

It is not an unprimeable number, because it can be changed into a prime (20428817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3840 + ... + 7456.

Almost surely, 2^20428816 is an apocalyptic number.

It is an amenable number.

20428816 is a deficient number, since it is larger than the sum of its proper divisors (19275116).

20428816 is a wasteful number, since it uses less digits than its factorization.

20428816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3978 (or 3972 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 20428816 is about 4519.8247753646. The cubic root of 20428816 is about 273.3680357817.

It can be divided in two parts, 204288 and 16, that added together give a square (204304 = 452²).

The spelling of 20428816 in words is "twenty million, four hundred twenty-eight thousand, eight hundred sixteen".