191331728640 has 576 divisors, whose sum is σ = 738086764800. Its totient is φ = 46653014016.

The previous prime is 191331728629. The next prime is 191331728663. The reversal of 191331728640 is 46827133191.

191331728640 is a `hidden beast` number, since 1 + 9 + 13 + 317 + 286 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 48969567 + ... + 48973473.

Almost surely, 2^191331728640 is an apocalyptic number.

191331728640 is a gapful number since it is divisible by the number (10) 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 191331728640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (369043382400).

191331728640 is an abundant number, since it is smaller than the sum of its proper divisors (546755036160).

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

191331728640 is a wasteful number, since it uses less digits than its factorization.

191331728640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4059 (or 4039 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 191331728640 in words is "one hundred ninety-one billion, three hundred thirty-one million, seven hundred twenty-eight thousand, six hundred forty".