531051821 has 2 divisors, whose sum is σ = 531051822. Its totient is φ = 531051820.

The previous prime is 531051811. The next prime is 531051841. The reversal of 531051821 is 128150135.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 297390025 + 233661796 = 17245^2 + 15286^2 .

It is a cyclic number.

It is not a de Polignac number, because 531051821 - 2⁶ = 531051757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (531051811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 265525910 + 265525911.

It is an arithmetic number, because the mean of its divisors is an integer number (265525911).

Almost surely, 2^531051821 is an apocalyptic number.

It is an amenable number.

531051821 is a deficient number, since it is larger than the sum of its proper divisors (1).

531051821 is an equidigital number, since it uses as much as digits as its factorization.

531051821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 26.

The square root of 531051821 is about 23044.5616360997. The cubic root of 531051821 is about 809.8022282993.

The spelling of 531051821 in words is "five hundred thirty-one million, fifty-one thousand, eight hundred twenty-one".