21320264263 has 4 divisors (see below), whose sum is σ = 21414186360. Its totient is φ = 21226342168.

The previous prime is 21320264237. The next prime is 21320264293. The reversal of 21320264263 is 36246202312.

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-21320264263 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 (21320264293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46960708 + ... + 46961161.

It is an arithmetic number, because the mean of its divisors is an integer number (5353546590).

Almost surely, 2^21320264263 is an apocalyptic number.

21320264263 is a deficient number, since it is larger than the sum of its proper divisors (93922097).

21320264263 is an equidigital number, since it uses as much as digits as its factorization.

21320264263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93922096.

The product of its (nonzero) digits is 20736, while the sum is 31.

Adding to 21320264263 its reverse (36246202312), we get a palindrome (57566466575).

The spelling of 21320264263 in words is "twenty-one billion, three hundred twenty million, two hundred sixty-four thousand, two hundred sixty-three".