531999999991 has 2 divisors, whose sum is σ = 531999999992. Its totient is φ = 531999999990.

The previous prime is 531999999983. The next prime is 532000000069. The reversal of 531999999991 is 199999999135.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 531999999991 - 2³ = 531999999983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (531999999901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 265999999995 + 265999999996.

It is an arithmetic number, because the mean of its divisors is an integer number (265999999996).

Almost surely, 2^531999999991 is an apocalyptic number.

531999999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

531999999991 is an equidigital number, since it uses as much as digits as its factorization.

531999999991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 645700815, while the sum is 82.

The spelling of 531999999991 in words is "five hundred thirty-one billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-one".