531291508861 has 2 divisors, whose sum is σ = 531291508862. Its totient is φ = 531291508860.

The previous prime is 531291508841. The next prime is 531291508919. The reversal of 531291508861 is 168805192135.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 334349932900 + 196941575961 = 578230^2 + 443781^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-531291508861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (531291508841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 265645754430 + 265645754431.

It is an arithmetic number, because the mean of its divisors is an integer number (265645754431).

Almost surely, 2^531291508861 is an apocalyptic number.

It is an amenable number.

531291508861 is a deficient number, since it is larger than the sum of its proper divisors (1).

531291508861 is an equidigital number, since it uses as much as digits as its factorization.

531291508861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 518400, while the sum is 49.

The spelling of 531291508861 in words is "five hundred thirty-one billion, two hundred ninety-one million, five hundred eight thousand, eight hundred sixty-one".