20206021 has 4 divisors (see below), whose sum is σ = 22042944. Its totient is φ = 18369100.

The previous prime is 20206019. The next prime is 20206037. The reversal of 20206021 is 12060202.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20206021 - 2¹ = 20206019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20205992 and 20206010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20206721) 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, 918445 + ... + 918466.

It is an arithmetic number, because the mean of its divisors is an integer number (5510736).

Almost surely, 2^20206021 is an apocalyptic number.

It is an amenable number.

20206021 is a deficient number, since it is larger than the sum of its proper divisors (1836923).

20206021 is a wasteful number, since it uses less digits than its factorization.

20206021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1836922.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20206021 is about 4495.1107884011. The cubic root of 20206021 is about 272.3706245550.

Adding to 20206021 its reverse (12060202), we get a palindrome (32266223).

The spelling of 20206021 in words is "twenty million, two hundred six thousand, twenty-one".