19779697791 has 48 divisors (see below), whose sum is σ = 32835336768. Its totient is φ = 11239488000.

The previous prime is 19779697787. The next prime is 19779697807.

19779697791 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 19779697791 - 2² = 19779697787 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19779697291) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10403941 + ... + 10405841.

It is an arithmetic number, because the mean of its divisors is an integer number (684069516).

Almost surely, 2^19779697791 is an apocalyptic number.

19779697791 is a deficient number, since it is larger than the sum of its proper divisors (13055638977).

19779697791 is a wasteful number, since it uses less digits than its factorization.

19779697791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2752 (or 2749 counting only the distinct ones).

The product of its digits is 94517766, while the sum is 72.

The spelling of 19779697791 in words is "nineteen billion, seven hundred seventy-nine million, six hundred ninety-seven thousand, seven hundred ninety-one".