191231280 has 160 divisors (see below), whose sum is σ = 667427520. Its totient is φ = 50948352.

The previous prime is 191231273. The next prime is 191231291. The reversal of 191231280 is 82132191.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 174414 + ... + 175506.

It is an arithmetic number, because the mean of its divisors is an integer number (4171422).

Almost surely, 2^191231280 is an apocalyptic number.

191231280 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 191231280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (333713760).

191231280 is an abundant number, since it is smaller than the sum of its proper divisors (476196240).

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

191231280 is an equidigital number, since it uses as much as digits as its factorization.

191231280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1127 (or 1103 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 191231280 is about 13828.6398463479. The cubic root of 191231280 is about 576.1288774121.

The spelling of 191231280 in words is "one hundred ninety-one million, two hundred thirty-one thousand, two hundred eighty".