191431240 has 192 divisors, whose sum is σ = 589498560. Its totient is φ = 54996480.

The previous prime is 191431189. The next prime is 191431241. The reversal of 191431240 is 42134191.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191431241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 279939 + ... + 280621.

It is an arithmetic number, because the mean of its divisors is an integer number (3070305).

Almost surely, 2^191431240 is an apocalyptic number.

191431240 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 191431240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294749280).

191431240 is an abundant number, since it is smaller than the sum of its proper divisors (398067320).

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

191431240 is a wasteful number, since it uses less digits than its factorization.

191431240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732 (or 721 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 191431240 is about 13835.8678802596. The cubic root of 191431240 is about 576.3296161893.

The spelling of 191431240 in words is "one hundred ninety-one million, four hundred thirty-one thousand, two hundred forty".