21374217563 has 4 divisors (see below), whose sum is σ = 21377832168. Its totient is φ = 21370602960.

The previous prime is 21374217509. The next prime is 21374217581. The reversal of 21374217563 is 36571247312.

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 21374217563 - 2¹⁶ = 21374152027 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21374217563.

It is not an unprimeable number, because it can be changed into a prime (21374217463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1798418 + ... + 1810263.

It is an arithmetic number, because the mean of its divisors is an integer number (5344458042).

Almost surely, 2^21374217563 is an apocalyptic number.

21374217563 is a deficient number, since it is larger than the sum of its proper divisors (3614605).

21374217563 is an equidigital number, since it uses as much as digits as its factorization.

21374217563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3614604.

The product of its digits is 211680, while the sum is 41.

The spelling of 21374217563 in words is "twenty-one billion, three hundred seventy-four million, two hundred seventeen thousand, five hundred sixty-three".