531303991 has 2 divisors, whose sum is σ = 531303992. Its totient is φ = 531303990.

The previous prime is 531303977. The next prime is 531304057. The reversal of 531303991 is 199303135.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 531303991 - 2²⁵ = 497749559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (531303911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 265651995 + 265651996.

It is an arithmetic number, because the mean of its divisors is an integer number (265651996).

Almost surely, 2^531303991 is an apocalyptic number.

531303991 is a deficient number, since it is larger than the sum of its proper divisors (1).

531303991 is an equidigital number, since it uses as much as digits as its factorization.

531303991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10935, while the sum is 34.

The square root of 531303991 is about 23050.0323427105. The cubic root of 531303991 is about 809.9303862340.

It can be divided in two parts, 53130 and 3991, that added together give a square (57121 = 239²).

The spelling of 531303991 in words is "five hundred thirty-one million, three hundred three thousand, nine hundred ninety-one".