21111101305 has 96 divisors (see below), whose sum is σ = 31427854848. Its totient is φ = 13329792000.

The previous prime is 21111101299. The next prime is 21111101309. The reversal of 21111101305 is 50310111112.

It is a happy number.

It is not a de Polignac number, because 21111101305 - 2¹¹ = 21111099257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111101309) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 90605469 + ... + 90605701.

It is an arithmetic number, because the mean of its divisors is an integer number (327373488).

Almost surely, 2^21111101305 is an apocalyptic number.

It is an amenable number.

21111101305 is a deficient number, since it is larger than the sum of its proper divisors (10316753543).

21111101305 is a wasteful number, since it uses less digits than its factorization.

21111101305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455 (or 436 counting only the distinct ones).

The product of its (nonzero) digits is 30, while the sum is 16.

Adding to 21111101305 its reverse (50310111112), we get a palindrome (71421212417).

The spelling of 21111101305 in words is "twenty-one billion, one hundred eleven million, one hundred one thousand, three hundred five".