531991939 has 4 divisors (see below), whose sum is σ = 533009656. Its totient is φ = 530974224.

The previous prime is 531991913. The next prime is 531991949. The reversal of 531991939 is 939199135.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-531991939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 531991892 and 531991901.

It is not an unprimeable number, because it can be changed into a prime (531991949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 508074 + ... + 509119.

It is an arithmetic number, because the mean of its divisors is an integer number (133252414).

Almost surely, 2^531991939 is an apocalyptic number.

531991939 is a deficient number, since it is larger than the sum of its proper divisors (1017717).

531991939 is a wasteful number, since it uses less digits than its factorization.

531991939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1017716.

The product of its digits is 295245, while the sum is 49.

The square root of 531991939 is about 23064.9504443430. The cubic root of 531991939 is about 810.2798093408.

The spelling of 531991939 in words is "five hundred thirty-one million, nine hundred ninety-one thousand, nine hundred thirty-nine".