21120100013 has 4 divisors (see below), whose sum is σ = 21120636348. Its totient is φ = 21119563680.

The previous prime is 21120099997. The next prime is 21120100039. The reversal of 21120100013 is 31000102112.

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 11278864804 + 9841235209 = 106202^2 + 99203^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120100013 - 2⁴ = 21120099997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120099967 and 21120100003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120100063) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203978 + ... + 289563.

It is an arithmetic number, because the mean of its divisors is an integer number (5280159087).

Almost surely, 2^21120100013 is an apocalyptic number.

It is an amenable number.

21120100013 is a deficient number, since it is larger than the sum of its proper divisors (536335).

21120100013 is an equidigital number, since it uses as much as digits as its factorization.

21120100013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536334.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21120100013 its reverse (31000102112), we get a palindrome (52120202125).

The spelling of 21120100013 in words is "twenty-one billion, one hundred twenty million, one hundred thousand, thirteen".