21167440717 has 4 divisors (see below), whose sum is σ = 21483372736. Its totient is φ = 20851508700.

The previous prime is 21167440711. The next prime is 21167440733. The reversal of 21167440717 is 71704476112.

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 not a de Polignac number, because 21167440717 - 2¹⁵ = 21167407949 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 21167440717.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21167440711) 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, 157965909 + ... + 157966042.

It is an arithmetic number, because the mean of its divisors is an integer number (5370843184).

Almost surely, 2^21167440717 is an apocalyptic number.

It is an amenable number.

21167440717 is a deficient number, since it is larger than the sum of its proper divisors (315932019).

21167440717 is an equidigital number, since it uses as much as digits as its factorization.

21167440717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315932018.

The product of its (nonzero) digits is 65856, while the sum is 40.

The spelling of 21167440717 in words is "twenty-one billion, one hundred sixty-seven million, four hundred forty thousand, seven hundred seventeen".