999923531 has 2 divisors, whose sum is σ = 999923532. Its totient is φ = 999923530.

The previous prime is 999923501. The next prime is 999923537. The reversal of 999923531 is 135329999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999923531 - 2⁶ = 999923467 is a prime.

It is a super-2 number, since 2×999923531² = 1999694135695015922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999923531.

It is not a weakly prime, because it can be changed into another prime (999923537) 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 as a sum of consecutive naturals, namely, 499961765 + 499961766.

It is an arithmetic number, because the mean of its divisors is an integer number (499961766).

Almost surely, 2^999923531 is an apocalyptic number.

999923531 is a deficient number, since it is larger than the sum of its proper divisors (1).

999923531 is an equidigital number, since it uses as much as digits as its factorization.

999923531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 590490, while the sum is 50.

The square root of 999923531 is about 31621.5674975166. The cubic root of 999923531 is about 999.9745096836.

The spelling of 999923531 in words is "nine hundred ninety-nine million, nine hundred twenty-three thousand, five hundred thirty-one".