21320111305 has 8 divisors (see below), whose sum is σ = 25671453192. Its totient is φ = 16997875968.

The previous prime is 21320111291. The next prime is 21320111363. The reversal of 21320111305 is 50311102312.

It can be written as a sum of positive squares in 4 ways, for example, as 10037635344 + 11282475961 = 100188^2 + 106219^2 .

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 21320111305 - 2⁵ = 21320111273 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7275024 + ... + 7277953.

It is an arithmetic number, because the mean of its divisors is an integer number (3208931649).

Almost surely, 2^21320111305 is an apocalyptic number.

It is an amenable number.

21320111305 is a deficient number, since it is larger than the sum of its proper divisors (4351341887).

21320111305 is a wasteful number, since it uses less digits than its factorization.

21320111305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14553275.

The product of its (nonzero) digits is 180, while the sum is 19.

Adding to 21320111305 its reverse (50311102312), we get a palindrome (71631213617).

The spelling of 21320111305 in words is "twenty-one billion, three hundred twenty million, one hundred eleven thousand, three hundred five".