19923420773 has 4 divisors (see below), whose sum is σ = 20068847340. Its totient is φ = 19777994208.

The previous prime is 19923420749. The next prime is 19923420779. The reversal of 19923420773 is 37702432991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37702432991 = 23 ⋅1639236217.

It can be written as a sum of positive squares in 2 ways, for example, as 12937470049 + 6985950724 = 113743^2 + 83582^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19923420773 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 (19923420779) 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, 72713078 + ... + 72713351.

It is an arithmetic number, because the mean of its divisors is an integer number (5017211835).

Almost surely, 2^19923420773 is an apocalyptic number.

It is an amenable number.

19923420773 is a deficient number, since it is larger than the sum of its proper divisors (145426567).

19923420773 is a wasteful number, since it uses less digits than its factorization.

19923420773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145426566.

The product of its (nonzero) digits is 571536, while the sum is 47.

The spelling of 19923420773 in words is "nineteen billion, nine hundred twenty-three million, four hundred twenty thousand, seven hundred seventy-three".