21415311311 has 4 divisors (see below), whose sum is σ = 21417194232. Its totient is φ = 21413428392.

The previous prime is 21415311271. The next prime is 21415311341. The reversal of 21415311311 is 11311351412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21415311311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21415311341) 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, 924296 + ... + 947181.

It is an arithmetic number, because the mean of its divisors is an integer number (5354298558).

Almost surely, 2^21415311311 is an apocalyptic number.

21415311311 is a deficient number, since it is larger than the sum of its proper divisors (1882921).

21415311311 is a wasteful number, since it uses less digits than its factorization.

21415311311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1882920.

The product of its digits is 360, while the sum is 23.

Adding to 21415311311 its reverse (11311351412), we get a palindrome (32726662723).

The spelling of 21415311311 in words is "twenty-one billion, four hundred fifteen million, three hundred eleven thousand, three hundred eleven".