21046968791 has 4 divisors (see below), whose sum is σ = 21047632752. Its totient is φ = 21046304832.

The previous prime is 21046968769. The next prime is 21046968797. The reversal of 21046968791 is 19786964012.

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 21046968791 - 2¹⁸ = 21046706647 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 (21046968797) 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, 281915 + ... + 348668.

It is an arithmetic number, because the mean of its divisors is an integer number (5261908188).

Almost surely, 2^21046968791 is an apocalyptic number.

21046968791 is a deficient number, since it is larger than the sum of its proper divisors (663961).

21046968791 is an equidigital number, since it uses as much as digits as its factorization.

21046968791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663960.

The product of its (nonzero) digits is 1306368, while the sum is 53.

The spelling of 21046968791 in words is "twenty-one billion, forty-six million, nine hundred sixty-eight thousand, seven hundred ninety-one".