21231201311 has 8 divisors (see below), whose sum is σ = 21442572624. Its totient is φ = 21020849280.

The previous prime is 21231201301. The next prime is 21231201317. The reversal of 21231201311 is 11310213212.

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-21231201311 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 21231201311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231201317) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212921 + ... + 296306.

It is an arithmetic number, because the mean of its divisors is an integer number (2680321578).

Almost surely, 2^21231201311 is an apocalyptic number.

21231201311 is a deficient number, since it is larger than the sum of its proper divisors (211371313).

21231201311 is a wasteful number, since it uses less digits than its factorization.

21231201311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509641.

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

Adding to 21231201311 its reverse (11310213212), we get a palindrome (32541414523).

The spelling of 21231201311 in words is "twenty-one billion, two hundred thirty-one million, two hundred one thousand, three hundred eleven".