19779340694 has 4 divisors (see below), whose sum is σ = 29669011044. Its totient is φ = 9889670346.

The previous prime is 19779340667. The next prime is 19779340709. The reversal of 19779340694 is 49604397791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49604397791 = 13 ⋅3815722907.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 4944835172 + ... + 4944835175.

It is an arithmetic number, because the mean of its divisors is an integer number (7417252761).

Almost surely, 2^19779340694 is an apocalyptic number.

19779340694 is a deficient number, since it is larger than the sum of its proper divisors (9889670350).

19779340694 is an equidigital number, since it uses as much as digits as its factorization.

19779340694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9889670349.

The product of its (nonzero) digits is 10287648, while the sum is 59.

The spelling of 19779340694 in words is "nineteen billion, seven hundred seventy-nine million, three hundred forty thousand, six hundred ninety-four".