1009991444 has 24 divisors (see below), whose sum is σ = 2203618368. Its totient is φ = 393503040.

The previous prime is 1009991443. The next prime is 1009991449. The reversal of 1009991444 is 4441999001.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1009991443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1639289 + ... + 1639904.

It is an arithmetic number, because the mean of its divisors is an integer number (91817432).

Almost surely, 2^1009991444 is an apocalyptic number.

1009991444 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1009991444 is an abundant number, since it is smaller than the sum of its proper divisors (1193626924).

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

1009991444 is a wasteful number, since it uses less digits than its factorization.

1009991444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3279215 (or 3279213 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 1009991444 is about 31780.3625529980. The cubic root of 1009991444 is about 1003.3194503904.

The spelling of 1009991444 in words is "one billion, nine million, nine hundred ninety-one thousand, four hundred forty-four".