213013021 has 4 divisors (see below), whose sum is σ = 229398652. Its totient is φ = 196627392.

The previous prime is 213012991. The next prime is 213013049. The reversal of 213013021 is 120310312.

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 58905625 + 154107396 = 7675^2 + 12414^2 .

It is not a de Polignac number, because 213013021 - 2⁹ = 213012509 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 16385617 = 213013021 / (2 + 1 + 3 + 0 + 1 + 3 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213012992 and 213013010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213013061) 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 3 ways as a sum of consecutive naturals, for example, 8192796 + ... + 8192821.

It is an arithmetic number, because the mean of its divisors is an integer number (57349663).

Almost surely, 2^213013021 is an apocalyptic number.

It is an amenable number.

213013021 is a deficient number, since it is larger than the sum of its proper divisors (16385631).

213013021 is a wasteful number, since it uses less digits than its factorization.

213013021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16385630.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 213013021 is about 14594.9656046186. The cubic root of 213013021 is about 597.2214311585.

Adding to 213013021 its reverse (120310312), we get a palindrome (333323333).

It can be divided in two parts, 2130 and 13021, that added together give a palindrome (15151).

The spelling of 213013021 in words is "two hundred thirteen million, thirteen thousand, twenty-one".