191980 has 24 divisors (see below), whose sum is σ = 418320. Its totient is φ = 73920.

The previous prime is 191977. The next prime is 191999. The reversal of 191980 is 89191.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 415 + ... + 745.

It is an arithmetic number, because the mean of its divisors is an integer number (17430).

2¹⁹¹⁹⁸⁰ is an apocalyptic number.

191980 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 191980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (209160).

191980 is an abundant number, since it is smaller than the sum of its proper divisors (226340).

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

191980 is a wasteful number, since it uses less digits than its factorization.

191980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 191980 is about 438.1552236366. The cubic root of 191980 is about 57.6879796183.

The spelling of 191980 in words is "one hundred ninety-one thousand, nine hundred eighty".