21369280663 has 4 divisors (see below), whose sum is σ = 22106152440. Its totient is φ = 20632408888.

The previous prime is 21369280661. The next prime is 21369280693. The reversal of 21369280663 is 36608296312.

It is a happy number.

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 21369280663 - 2¹ = 21369280661 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 (21369280661) 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, 368435845 + ... + 368435902.

It is an arithmetic number, because the mean of its divisors is an integer number (5526538110).

Almost surely, 2^21369280663 is an apocalyptic number.

21369280663 is a deficient number, since it is larger than the sum of its proper divisors (736871777).

21369280663 is an equidigital number, since it uses as much as digits as its factorization.

21369280663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736871776.

The product of its (nonzero) digits is 559872, while the sum is 46.

The spelling of 21369280663 in words is "twenty-one billion, three hundred sixty-nine million, two hundred eighty thousand, six hundred sixty-three".