191897216 has 64 divisors (see below), whose sum is σ = 444197760. Its totient is φ = 80870400.

The previous prime is 191897203. The next prime is 191897219. The reversal of 191897216 is 612798191.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (191897219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52901 + ... + 56411.

It is an arithmetic number, because the mean of its divisors is an integer number (6940590).

Almost surely, 2^191897216 is an apocalyptic number.

191897216 is a gapful number since it is divisible by the number (16) 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 191897216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (222098880).

191897216 is an abundant number, since it is smaller than the sum of its proper divisors (252300544).

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

191897216 is an equidigital number, since it uses as much as digits as its factorization.

191897216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3593 (or 3581 counting only the distinct ones).

The product of its digits is 54432, while the sum is 44.

The square root of 191897216 is about 13852.6970659146. The cubic root of 191897216 is about 576.7968651783.

The spelling of 191897216 in words is "one hundred ninety-one million, eight hundred ninety-seven thousand, two hundred sixteen".