21534201111 has 12 divisors (see below), whose sum is σ = 29736490472. Its totient is φ = 13861093344.

The previous prime is 21534201107. The next prime is 21534201127. The reversal of 21534201111 is 11110243512.

It is not a de Polignac number, because 21534201111 - 2² = 21534201107 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 (21534205111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4265056 + ... + 4270101.

Almost surely, 2^21534201111 is an apocalyptic number.

21534201111 is a deficient number, since it is larger than the sum of its proper divisors (8202289361).

21534201111 is an equidigital number, since it uses as much as digits as its factorization.

21534201111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8535218 (or 8535189 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 21.

Adding to 21534201111 its reverse (11110243512), we get a palindrome (32644444623).

The spelling of 21534201111 in words is "twenty-one billion, five hundred thirty-four million, two hundred one thousand, one hundred eleven".