19918079 has 4 divisors (see below), whose sum is σ = 20019384. Its totient is φ = 19816776.

The previous prime is 19918057. The next prime is 19918081. The reversal of 19918079 is 97081991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97081991 = 571 ⋅170021.

It is a cyclic number.

It is not a de Polignac number, because 19918079 - 2¹⁶ = 19852543 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 (19918039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50357 + ... + 50750.

It is an arithmetic number, because the mean of its divisors is an integer number (5004846).

Almost surely, 2^19918079 is an apocalyptic number.

19918079 is a deficient number, since it is larger than the sum of its proper divisors (101305).

19918079 is a wasteful number, since it uses less digits than its factorization.

19918079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101304.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 19918079 is about 4462.9675105248. The cubic root of 19918079 is about 271.0706414791.

The spelling of 19918079 in words is "nineteen million, nine hundred eighteen thousand, seventy-nine".