8213531 has 2 divisors, whose sum is σ = 8213532. Its totient is φ = 8213530.

The previous prime is 8213503. The next prime is 8213549. The reversal of 8213531 is 1353128.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8213531 - 2¹⁸ = 7951387 is a prime.

It is a super-2 number, since 2×8213531² = 134924182975922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 8213497 and 8213506.

It is not a weakly prime, because it can be changed into another prime (8213581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4106765 + 4106766.

It is an arithmetic number, because the mean of its divisors is an integer number (4106766).

Almost surely, 2^8213531 is an apocalyptic number.

8213531 is a deficient number, since it is larger than the sum of its proper divisors (1).

8213531 is an equidigital number, since it uses as much as digits as its factorization.

8213531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 720, while the sum is 23.

The square root of 8213531 is about 2865.9258538909. The cubic root of 8213531 is about 201.7638238981.

Adding to 8213531 its reverse (1353128), we get a palindrome (9566659).

The spelling of 8213531 in words is "eight million, two hundred thirteen thousand, five hundred thirty-one".