21199707673 has 4 divisors (see below), whose sum is σ = 21203565568. Its totient is φ = 21195849780.

The previous prime is 21199707667. The next prime is 21199707677. The reversal of 21199707673 is 37670799112.

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 21199707673 - 2⁹ = 21199707161 is a prime.

It is a super-3 number, since 3×21199707673³ (a number of 32 digits) contains 333 as substring.

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 21199707673.

It is not an unprimeable number, because it can be changed into a prime (21199707677) 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, 1920693 + ... + 1931698.

It is an arithmetic number, because the mean of its divisors is an integer number (5300891392).

Almost surely, 2^21199707673 is an apocalyptic number.

It is an amenable number.

21199707673 is a deficient number, since it is larger than the sum of its proper divisors (3857895).

21199707673 is an equidigital number, since it uses as much as digits as its factorization.

21199707673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3857894.

The product of its (nonzero) digits is 1000188, while the sum is 52.

The spelling of 21199707673 in words is "twenty-one billion, one hundred ninety-nine million, seven hundred seven thousand, six hundred seventy-three".