2001165399 has 16 divisors (see below), whose sum is σ = 2966031840. Its totient is φ = 1333506240.

The previous prime is 2001165391. The next prime is 2001165437. The reversal of 2001165399 is 9935611002.

2001165399 is a `hidden beast` number, since 2 + 0 + 0 + 116 + 539 + 9 = 666.

It is not a de Polignac number, because 2001165399 - 2³ = 2001165391 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001165391) 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 15 ways as a sum of consecutive naturals, for example, 48589 + ... + 79769.

It is an arithmetic number, because the mean of its divisors is an integer number (185376990).

Almost surely, 2^2001165399 is an apocalyptic number.

2001165399 is a deficient number, since it is larger than the sum of its proper divisors (964866441).

2001165399 is a wasteful number, since it uses less digits than its factorization.

2001165399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33567 (or 33561 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 2001165399 is about 44734.3872093941. The cubic root of 2001165399 is about 1260.1657208331.

The spelling of 2001165399 in words is "two billion, one million, one hundred sixty-five thousand, three hundred ninety-nine".