1001439999 has 18 divisors (see below), whose sum is σ = 1682692440. Its totient is φ = 572251176.

The previous prime is 1001439983. The next prime is 1001440021. The reversal of 1001439999 is 9999341001.

It is not a de Polignac number, because 1001439999 - 2⁴ = 1001439983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001439799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1134979 + ... + 1135860.

Almost surely, 2^1001439999 is an apocalyptic number.

1001439999 is a deficient number, since it is larger than the sum of its proper divisors (681252441).

1001439999 is a wasteful number, since it uses less digits than its factorization.

1001439999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2270859 (or 2270849 counting only the distinct ones).

The product of its (nonzero) digits is 78732, while the sum is 45.

The square root of 1001439999 is about 31645.5367943096. The cubic root of 1001439999 is about 1000.4797694511.

The spelling of 1001439999 in words is "one billion, one million, four hundred thirty-nine thousand, nine hundred ninety-nine".