191397978000 has 480 divisors, whose sum is σ = 695812965120. Its totient is φ = 50850892800.

The previous prime is 191397977987. The next prime is 191397978017. The reversal of 191397978000 is 879793191.

191397978000 is a `hidden beast` number, since 1 + 91 + 397 + 97 + 80 + 0 + 0 = 666.

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 (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 174473452 + ... + 174474548.

It is an arithmetic number, because the mean of its divisors is an integer number (1449610344).

Almost surely, 2^191397978000 is an apocalyptic number.

191397978000 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 191397978000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (347906482560).

191397978000 is an abundant number, since it is smaller than the sum of its proper divisors (504414987120).

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

191397978000 is a wasteful number, since it uses less digits than its factorization.

191397978000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1494 (or 1466 counting only the distinct ones).

The product of its (nonzero) digits is 857304, while the sum is 54.

The spelling of 191397978000 in words is "one hundred ninety-one billion, three hundred ninety-seven million, nine hundred seventy-eight thousand".