531121901 has 2 divisors, whose sum is σ = 531121902. Its totient is φ = 531121900.

The previous prime is 531121891. The next prime is 531121951. The reversal of 531121901 is 109121135.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 430521001 + 100600900 = 20749^2 + 10030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-531121901 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (531121951) 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 as a sum of consecutive naturals, namely, 265560950 + 265560951.

It is an arithmetic number, because the mean of its divisors is an integer number (265560951).

Almost surely, 2^531121901 is an apocalyptic number.

It is an amenable number.

531121901 is a deficient number, since it is larger than the sum of its proper divisors (1).

531121901 is an equidigital number, since it uses as much as digits as its factorization.

531121901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 270, while the sum is 23.

The square root of 531121901 is about 23046.0821182256. The cubic root of 531121901 is about 809.8378484540.

The spelling of 531121901 in words is "five hundred thirty-one million, one hundred twenty-one thousand, nine hundred one".