191440 has 20 divisors (see below), whose sum is σ = 445284. Its totient is φ = 76544.

The previous prime is 191413. The next prime is 191441. The reversal of 191440 is 44191.

It can be written as a sum of positive squares in 2 ways, for example, as 28224 + 163216 = 168^2 + 404^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1117 + ... + 1276.

2¹⁹¹⁴⁴⁰ is an apocalyptic number.

191440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191440 is an abundant number, since it is smaller than the sum of its proper divisors (253844).

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

191440 is a wasteful number, since it uses less digits than its factorization.

191440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2406 (or 2400 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 191440 is about 437.5385697284. The cubic root of 191440 is about 57.6338407110.

The spelling of 191440 in words is "one hundred ninety-one thousand, four hundred forty".