19186664238 has 96 divisors (see below), whose sum is σ = 49504815360. Its totient is φ = 5455719360.

The previous prime is 19186664137. The next prime is 19186664251. The reversal of 19186664238 is 83246668191.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 704458 + ... + 731186.

It is an arithmetic number, because the mean of its divisors is an integer number (515675160).

Almost surely, 2^19186664238 is an apocalyptic number.

19186664238 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19186664238, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24752407680).

19186664238 is an abundant number, since it is smaller than the sum of its proper divisors (30318151122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19186664238 is a wasteful number, since it uses less digits than its factorization.

19186664238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26964 (or 26952 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 54.

The spelling of 19186664238 in words is "nineteen billion, one hundred eighty-six million, six hundred sixty-four thousand, two hundred thirty-eight".