21165496017 has 4 divisors (see below), whose sum is σ = 28220661360. Its totient is φ = 14110330676.

The previous prime is 21165496013. The next prime is 21165496031. The reversal of 21165496017 is 71069456112.

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 21165496017 - 2² = 21165496013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21165496017.

It is not an unprimeable number, because it can be changed into a prime (21165496013) 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, 3527582667 + ... + 3527582672.

It is an arithmetic number, because the mean of its divisors is an integer number (7055165340).

Almost surely, 2^21165496017 is an apocalyptic number.

It is an amenable number.

21165496017 is a deficient number, since it is larger than the sum of its proper divisors (7055165343).

21165496017 is an equidigital number, since it uses as much as digits as its factorization.

21165496017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7055165342.

The product of its (nonzero) digits is 90720, while the sum is 42.

The spelling of 21165496017 in words is "twenty-one billion, one hundred sixty-five million, four hundred ninety-six thousand, seventeen".