21111033311 has 2 divisors, whose sum is σ = 21111033312. Its totient is φ = 21111033310.

The previous prime is 21111033289. The next prime is 21111033341. The reversal of 21111033311 is 11333011112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111033311 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21111033311.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111033341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555516655 + 10555516656.

It is an arithmetic number, because the mean of its divisors is an integer number (10555516656).

Almost surely, 2^21111033311 is an apocalyptic number.

21111033311 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111033311 is an equidigital number, since it uses as much as digits as its factorization.

21111033311 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 17.

Adding to 21111033311 its reverse (11333011112), we get a palindrome (32444044423).

The spelling of 21111033311 in words is "twenty-one billion, one hundred eleven million, thirty-three thousand, three hundred eleven".