21320563065 has 8 divisors (see below), whose sum is σ = 34112900928. Its totient is φ = 11370966960.

The previous prime is 21320563063. The next prime is 21320563067. The reversal of 21320563065 is 56036502312.

It is an interprime number because it is at equal distance from previous prime (21320563063) and next prime (21320563067).

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

It is not a de Polignac number, because 21320563065 - 2¹ = 21320563063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21320563063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 710685421 + ... + 710685450.

It is an arithmetic number, because the mean of its divisors is an integer number (4264112616).

Almost surely, 2^21320563065 is an apocalyptic number.

It is an amenable number.

21320563065 is a deficient number, since it is larger than the sum of its proper divisors (12792337863).

21320563065 is a wasteful number, since it uses less digits than its factorization.

21320563065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1421370879.

The product of its (nonzero) digits is 32400, while the sum is 33.

The spelling of 21320563065 in words is "twenty-one billion, three hundred twenty million, five hundred sixty-three thousand, sixty-five".