21324339091 has 4 divisors (see below), whose sum is σ = 23262915384. Its totient is φ = 19385762800.

The previous prime is 21324339083. The next prime is 21324339107. The reversal of 21324339091 is 19093342312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21324339091 - 2³ = 21324339083 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21324339091.

It is not an unprimeable number, because it can be changed into a prime (21324339041) 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, 969288130 + ... + 969288151.

It is an arithmetic number, because the mean of its divisors is an integer number (5815728846).

Almost surely, 2^21324339091 is an apocalyptic number.

21324339091 is a deficient number, since it is larger than the sum of its proper divisors (1938576293).

21324339091 is a wasteful number, since it uses less digits than its factorization.

21324339091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1938576292.

The product of its (nonzero) digits is 34992, while the sum is 37.

The spelling of 21324339091 in words is "twenty-one billion, three hundred twenty-four million, three hundred thirty-nine thousand, ninety-one".