1009191940 has 48 divisors (see below), whose sum is σ = 2189835648. Its totient is φ = 390426624.

The previous prime is 1009191929. The next prime is 1009191959. The reversal of 1009191940 is 491919001.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1009191896 and 1009191905.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 82884 + ... + 94276.

It is an arithmetic number, because the mean of its divisors is an integer number (45621576).

Almost surely, 2^1009191940 is an apocalyptic number.

1009191940 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 1009191940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1094917824).

1009191940 is an abundant number, since it is smaller than the sum of its proper divisors (1180643708).

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

1009191940 is a wasteful number, since it uses less digits than its factorization.

1009191940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11548 (or 11546 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 1009191940 is about 31767.7814774655. The cubic root of 1009191940 is about 1003.0546396757.

The spelling of 1009191940 in words is "one billion, nine million, one hundred ninety-one thousand, nine hundred forty".