19161772128 has 120 divisors (see below), whose sum is σ = 56714388192. Its totient is φ = 6346439424.

The previous prime is 19161772073. The next prime is 19161772151. The reversal of 19161772128 is 82127716191.

It is a happy number.

19161772128 is a `hidden beast` number, since 1 + 9 + 1 + 617 + 7 + 2 + 1 + 28 = 666.

It is a super-2 number, since 2×19161772128² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 383401 + ... + 430487.

Almost surely, 2^19161772128 is an apocalyptic number.

19161772128 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19161772128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28357194096).

19161772128 is an abundant number, since it is smaller than the sum of its proper divisors (37552616064).

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

19161772128 is a wasteful number, since it uses less digits than its factorization.

19161772128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47266 (or 47249 counting only the distinct ones).

The product of its digits is 84672, while the sum is 45.

The spelling of 19161772128 in words is "nineteen billion, one hundred sixty-one million, seven hundred seventy-two thousand, one hundred twenty-eight".