21431064799 has 4 divisors (see below), whose sum is σ = 21434964736. Its totient is φ = 21427164864.

The previous prime is 21431064797. The next prime is 21431064829. The reversal of 21431064799 is 99746013412.

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 21431064799 - 2¹ = 21431064797 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 (21431064797) 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, 1941714 + ... + 1952719.

It is an arithmetic number, because the mean of its divisors is an integer number (5358741184).

Almost surely, 2^21431064799 is an apocalyptic number.

21431064799 is a deficient number, since it is larger than the sum of its proper divisors (3899937).

21431064799 is an equidigital number, since it uses as much as digits as its factorization.

21431064799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3899936.

The product of its (nonzero) digits is 326592, while the sum is 46.

The spelling of 21431064799 in words is "twenty-one billion, four hundred thirty-one million, sixty-four thousand, seven hundred ninety-nine".