1939444009 has 4 divisors (see below), whose sum is σ = 1944846720. Its totient is φ = 1934041300.

The previous prime is 1939443983. The next prime is 1939444021. The reversal of 1939444009 is 9004449391.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1939444009 - 2⁵ = 1939443977 is a prime.

It is a super-2 number, since 2×1939444009² = 7522886128091984162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1939484009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2700817 + ... + 2701534.

It is an arithmetic number, because the mean of its divisors is an integer number (486211680).

Almost surely, 2^1939444009 is an apocalyptic number.

It is an amenable number.

1939444009 is a deficient number, since it is larger than the sum of its proper divisors (5402711).

1939444009 is an equidigital number, since it uses as much as digits as its factorization.

1939444009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5402710.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 1939444009 is about 44039.1190761123. The cubic root of 1939444009 is about 1247.0745473091.

The spelling of 1939444009 in words is "one billion, nine hundred thirty-nine million, four hundred forty-four thousand, nine".