19918382557 has 8 divisors (see below), whose sum is σ = 20391339584. Its totient is φ = 19445868288.

The previous prime is 19918382543. The next prime is 19918382581. The reversal of 19918382557 is 75528381991.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19918382557 - 2²³ = 19909993949 is a prime.

It is the 141133-rd Hogben number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19918382527) by changing a digit.

It is a nontrivial repunit in base 141132.

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 7 ways as a sum of consecutive naturals, for example, 18753 + ... + 200470.

It is an arithmetic number, because the mean of its divisors is an integer number (2548917448).

Almost surely, 2^19918382557 is an apocalyptic number.

It is an amenable number.

19918382557 is a deficient number, since it is larger than the sum of its proper divisors (472957027).

19918382557 is a wasteful number, since it uses less digits than its factorization.

19918382557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221379.

The product of its digits is 5443200, while the sum is 58.

The spelling of 19918382557 in words is "nineteen billion, nine hundred eighteen million, three hundred eighty-two thousand, five hundred fifty-seven".