21091614911 has 4 divisors (see below), whose sum is σ = 21109177824. Its totient is φ = 21074052000.

The previous prime is 21091614889. The next prime is 21091614923. The reversal of 21091614911 is 11941619012.

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-21091614911 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 (21091614991) 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, 8779655 + ... + 8782056.

It is an arithmetic number, because the mean of its divisors is an integer number (5277294456).

Almost surely, 2^21091614911 is an apocalyptic number.

21091614911 is a deficient number, since it is larger than the sum of its proper divisors (17562913).

21091614911 is a wasteful number, since it uses less digits than its factorization.

21091614911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17562912.

The product of its (nonzero) digits is 3888, while the sum is 35.

The spelling of 21091614911 in words is "twenty-one billion, ninety-one million, six hundred fourteen thousand, nine hundred eleven".