21200120311 has 16 divisors (see below), whose sum is σ = 21758220000. Its totient is φ = 20649835008.

The previous prime is 21200120269. The next prime is 21200120321. The reversal of 21200120311 is 11302100212.

It is a cyclic number.

It is not a de Polignac number, because 21200120311 - 2²¹ = 21198023159 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21200120291 and 21200120300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200120321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7710565 + ... + 7713313.

It is an arithmetic number, because the mean of its divisors is an integer number (1359888750).

Almost surely, 2^21200120311 is an apocalyptic number.

21200120311 is a deficient number, since it is larger than the sum of its proper divisors (558099689).

21200120311 is a wasteful number, since it uses less digits than its factorization.

21200120311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4098.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21200120311 its reverse (11302100212), we get a palindrome (32502220523).

The spelling of 21200120311 in words is "twenty-one billion, two hundred million, one hundred twenty thousand, three hundred eleven".