19745504321 has 4 divisors (see below), whose sum is σ = 19749761712. Its totient is φ = 19741246932.

The previous prime is 19745504297. The next prime is 19745504329. The reversal of 19745504321 is 12340554791.

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 19745504321 - 2³⁰ = 18671762497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19745504329) 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, 2121731 + ... + 2131016.

It is an arithmetic number, because the mean of its divisors is an integer number (4937440428).

Almost surely, 2^19745504321 is an apocalyptic number.

It is an amenable number.

19745504321 is a deficient number, since it is larger than the sum of its proper divisors (4257391).

19745504321 is an equidigital number, since it uses as much as digits as its factorization.

19745504321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4257390.

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 19745504321 in words is "nineteen billion, seven hundred forty-five million, five hundred four thousand, three hundred twenty-one".