821875531 has 2 divisors, whose sum is σ = 821875532. Its totient is φ = 821875530.

The previous prime is 821875501. The next prime is 821875543. The reversal of 821875531 is 135578128.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 821875531 - 2²⁹ = 285004619 is a prime.

It is a super-2 number, since 2×821875531² = 1350958776913063922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (821875501) 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, 410937765 + 410937766.

It is an arithmetic number, because the mean of its divisors is an integer number (410937766).

Almost surely, 2^821875531 is an apocalyptic number.

821875531 is a deficient number, since it is larger than the sum of its proper divisors (1).

821875531 is an equidigital number, since it uses as much as digits as its factorization.

821875531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 67200, while the sum is 40.

The square root of 821875531 is about 28668.3716140279. The cubic root of 821875531 is about 936.7032281137.

The spelling of 821875531 in words is "eight hundred twenty-one million, eight hundred seventy-five thousand, five hundred thirty-one".