19745503891 has 8 divisors (see below), whose sum is σ = 19776078000. Its totient is φ = 19714951680.

The previous prime is 19745503829. The next prime is 19745503913. The reversal of 19745503891 is 19830554791.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19745503891 is a prime.

It is a super-2 number, since 2×19745503891² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19745503801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2829036 + ... + 2836006.

It is an arithmetic number, because the mean of its divisors is an integer number (2472009750).

Almost surely, 2^19745503891 is an apocalyptic number.

19745503891 is a deficient number, since it is larger than the sum of its proper divisors (30574109).

19745503891 is an equidigital number, since it uses as much as digits as its factorization.

19745503891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10949.

The product of its (nonzero) digits is 1360800, while the sum is 52.

The spelling of 19745503891 in words is "nineteen billion, seven hundred forty-five million, five hundred three thousand, eight hundred ninety-one".