21717771373 has 4 divisors (see below), whose sum is σ = 21750727680. Its totient is φ = 21684815068.

The previous prime is 21717771359. The next prime is 21717771377. The reversal of 21717771373 is 37317771712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21717771373 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 (21717771377) 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, 16477165 + ... + 16478482.

It is an arithmetic number, because the mean of its divisors is an integer number (5437681920).

Almost surely, 2^21717771373 is an apocalyptic number.

It is an amenable number.

21717771373 is a deficient number, since it is larger than the sum of its proper divisors (32956307).

21717771373 is an equidigital number, since it uses as much as digits as its factorization.

21717771373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32956306.

The product of its digits is 302526, while the sum is 46.

The spelling of 21717771373 in words is "twenty-one billion, seven hundred seventeen million, seven hundred seventy-one thousand, three hundred seventy-three".