19891247797 has 8 divisors (see below), whose sum is σ = 20038689792. Its totient is φ = 19744275600.

The previous prime is 19891247777. The next prime is 19891247807. The reversal of 19891247797 is 79774219891.

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

It is a cyclic number.

It is not a de Polignac number, because 19891247797 - 2¹⁹ = 19890723509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19891247777) 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 7 ways as a sum of consecutive naturals, for example, 32229 + ... + 202042.

It is an arithmetic number, because the mean of its divisors is an integer number (2504836224).

Almost surely, 2^19891247797 is an apocalyptic number.

It is an amenable number.

19891247797 is a deficient number, since it is larger than the sum of its proper divisors (147441995).

19891247797 is a wasteful number, since it uses less digits than its factorization.

19891247797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234899.

The product of its digits is 16003008, while the sum is 64.

The spelling of 19891247797 in words is "nineteen billion, eight hundred ninety-one million, two hundred forty-seven thousand, seven hundred ninety-seven".