191940840 has 576 divisors, whose sum is σ = 836559360. Its totient is φ = 39191040.

The previous prime is 191940839. The next prime is 191940841. The reversal of 191940840 is 48049191.

It is an interprime number because it is at equal distance from previous prime (191940839) and next prime (191940841).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 191940795 and 191940804.

It is not an unprimeable number, because it can be changed into a prime (191940841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 6191625 + ... + 6191655.

It is an arithmetic number, because the mean of its divisors is an integer number (1452360).

Almost surely, 2^191940840 is an apocalyptic number.

191940840 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 191940840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (418279680).

191940840 is an abundant number, since it is smaller than the sum of its proper divisors (644618520).

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

191940840 is a wasteful number, since it uses less digits than its factorization.

191940840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 191940840 is about 13854.2715434627. The cubic root of 191940840 is about 576.8405696164.

The spelling of 191940840 in words is "one hundred ninety-one million, nine hundred forty thousand, eight hundred forty".