20446021 has 4 divisors (see below), whose sum is σ = 20486700. Its totient is φ = 20405344.

The previous prime is 20446009. The next prime is 20446031. The reversal of 20446021 is 12064402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18792225 + 1653796 = 4335^2 + 1286^2 .

It is a cyclic number.

It is not a de Polignac number, because 20446021 - 2⁵ = 20445989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20446021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20446001) 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, 19576 + ... + 20593.

It is an arithmetic number, because the mean of its divisors is an integer number (5121675).

Almost surely, 2^20446021 is an apocalyptic number.

It is an amenable number.

20446021 is a deficient number, since it is larger than the sum of its proper divisors (40679).

20446021 is an equidigital number, since it uses as much as digits as its factorization.

20446021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40678.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 20446021 is about 4521.7276565490. The cubic root of 20446021 is about 273.4447571037. Note that the first 3 decimals are identical.

It can be divided in two parts, 204 and 46021, that added together give a square (46225 = 215²).

The spelling of 20446021 in words is "twenty million, four hundred forty-six thousand, twenty-one".