21643012111 has 8 divisors (see below), whose sum is σ = 25532770304. Its totient is φ = 17952728760.

The previous prime is 21643012099. The next prime is 21643012117. The reversal of 21643012111 is 11121034612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21643012111 - 2²³ = 21634623503 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 (21643012117) 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, 49868475 + ... + 49868908.

It is an arithmetic number, because the mean of its divisors is an integer number (3191596288).

Almost surely, 2^21643012111 is an apocalyptic number.

21643012111 is a deficient number, since it is larger than the sum of its proper divisors (3889758193).

21643012111 is an equidigital number, since it uses as much as digits as its factorization.

21643012111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99737421.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 21643012111 its reverse (11121034612), we get a palindrome (32764046723).

The spelling of 21643012111 in words is "twenty-one billion, six hundred forty-three million, twelve thousand, one hundred eleven".