20213021 has 8 divisors (see below), whose sum is σ = 21439104. Its totient is φ = 19015920.

The previous prime is 20212991. The next prime is 20213047. The reversal of 20213021 is 12031202.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20213021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20212993 and 20213011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20213071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5801 + ... + 8606.

It is an arithmetic number, because the mean of its divisors is an integer number (2679888).

Almost surely, 2^20213021 is an apocalyptic number.

It is an amenable number.

20213021 is a deficient number, since it is larger than the sum of its proper divisors (1226083).

20213021 is a wasteful number, since it uses less digits than its factorization.

20213021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14491.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 20213021 is about 4495.8893447237. The cubic root of 20213021 is about 272.4020735020.

Adding to 20213021 its reverse (12031202), we get a palindrome (32244223).

The spelling of 20213021 in words is "twenty million, two hundred thirteen thousand, twenty-one".