21123201311 has 8 divisors (see below), whose sum is σ = 22045271040. Its totient is φ = 20201437432.

The previous prime is 21123201289. The next prime is 21123201343. The reversal of 21123201311 is 11310232112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123201311 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21123201311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123201361) 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 7 ways as a sum of consecutive naturals, for example, 70730 + ... + 217368.

It is an arithmetic number, because the mean of its divisors is an integer number (2755658880).

Almost surely, 2^21123201311 is an apocalyptic number.

21123201311 is a deficient number, since it is larger than the sum of its proper divisors (922069729).

21123201311 is a wasteful number, since it uses less digits than its factorization.

21123201311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152925.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21123201311 its reverse (11310232112), we get a palindrome (32433433423).

The spelling of 21123201311 in words is "twenty-one billion, one hundred twenty-three million, two hundred one thousand, three hundred eleven".