21000120213 has 16 divisors (see below), whose sum is σ = 29863641600. Its totient is φ = 13080362496.

The previous prime is 21000120187. The next prime is 21000120217. The reversal of 21000120213 is 31202100012.

It is not a de Polignac number, because 21000120213 - 2⁸ = 21000119957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000120217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1495813 + ... + 1509786.

It is an arithmetic number, because the mean of its divisors is an integer number (1866477600).

Almost surely, 2^21000120213 is an apocalyptic number.

It is an amenable number.

21000120213 is a deficient number, since it is larger than the sum of its proper divisors (8863521387).

21000120213 is a wasteful number, since it uses less digits than its factorization.

21000120213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3005756.

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21000120213 its reverse (31202100012), we get a palindrome (52202220225).

The spelling of 21000120213 in words is "twenty-one billion, one hundred twenty thousand, two hundred thirteen".