20211013 has 4 divisors (see below), whose sum is σ = 20223148. Its totient is φ = 20198880.

The previous prime is 20211007. The next prime is 20211031. The reversal of 20211013 is 31011202.

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 9042049 + 11168964 = 3007^2 + 3342^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20211013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211613) 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, 3078 + ... + 7063.

It is an arithmetic number, because the mean of its divisors is an integer number (5055787).

Almost surely, 2^20211013 is an apocalyptic number.

It is an amenable number.

20211013 is a deficient number, since it is larger than the sum of its proper divisors (12135).

20211013 is a wasteful number, since it uses less digits than its factorization.

20211013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12134.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 20211013 is about 4495.6660240725. Note that the first 3 decimals coincide. The cubic root of 20211013 is about 272.3930528897.

Adding to 20211013 its reverse (31011202), we get a palindrome (51222215).

The spelling of 20211013 in words is "twenty million, two hundred eleven thousand, thirteen".