21761846399 has 4 divisors (see below), whose sum is σ = 21762312264. Its totient is φ = 21761380536.

The previous prime is 21761846377. The next prime is 21761846411. The reversal of 21761846399 is 99364816712.

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-21761846399 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 (21761849399) 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, 153932 + ... + 259265.

It is an arithmetic number, because the mean of its divisors is an integer number (5440578066).

Almost surely, 2^21761846399 is an apocalyptic number.

21761846399 is a deficient number, since it is larger than the sum of its proper divisors (465865).

21761846399 is an equidigital number, since it uses as much as digits as its factorization.

21761846399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465864.

The product of its digits is 3919104, while the sum is 56.

The spelling of 21761846399 in words is "twenty-one billion, seven hundred sixty-one million, eight hundred forty-six thousand, three hundred ninety-nine".