19213830721 has 4 divisors (see below), whose sum is σ = 19833631744. Its totient is φ = 18594029700.

The previous prime is 19213830707. The next prime is 19213830733. The reversal of 19213830721 is 12703831291.

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 19213830721 - 2¹⁷ = 19213699649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19213830761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 309900465 + ... + 309900526.

It is an arithmetic number, because the mean of its divisors is an integer number (4958407936).

Almost surely, 2^19213830721 is an apocalyptic number.

It is an amenable number.

19213830721 is a deficient number, since it is larger than the sum of its proper divisors (619801023).

19213830721 is an equidigital number, since it uses as much as digits as its factorization.

19213830721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619801022.

The product of its (nonzero) digits is 18144, while the sum is 37.

The spelling of 19213830721 in words is "nineteen billion, two hundred thirteen million, eight hundred thirty thousand, seven hundred twenty-one".