19720079 has 4 divisors (see below), whose sum is σ = 19729776. Its totient is φ = 19710384.

The previous prime is 19720073. The next prime is 19720093. The reversal of 19720079 is 97002791.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 97002791 = 89 ⋅1089919.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19720079 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 (19720073) 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, 494 + ... + 6299.

It is an arithmetic number, because the mean of its divisors is an integer number (4932444).

Almost surely, 2^19720079 is an apocalyptic number.

19720079 is a deficient number, since it is larger than the sum of its proper divisors (9697).

19720079 is an equidigital number, since it uses as much as digits as its factorization.

19720079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9696.

The product of its (nonzero) digits is 7938, while the sum is 35.

The square root of 19720079 is about 4440.7295571786. The cubic root of 19720079 is about 270.1694364019.

The spelling of 19720079 in words is "nineteen million, seven hundred twenty thousand, seventy-nine".