8521531 has 4 divisors (see below), whose sum is σ = 8527464. Its totient is φ = 8515600.

The previous prime is 8521501. The next prime is 8521561. The reversal of 8521531 is 1351258.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1351258 = 2 ⋅675629.

It is an interprime number because it is at equal distance from previous prime (8521501) and next prime (8521561).

It is a cyclic number.

It is not a de Polignac number, because 8521531 - 2¹³ = 8513339 is a prime.

It is a super-2 number, since 2×8521531² = 145232981167922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 8521496 and 8521505.

It is not an unprimeable number, because it can be changed into a prime (8521501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 696 + ... + 4186.

It is an arithmetic number, because the mean of its divisors is an integer number (2131866).

Almost surely, 2^8521531 is an apocalyptic number.

8521531 is a deficient number, since it is larger than the sum of its proper divisors (5933).

8521531 is a wasteful number, since it uses less digits than its factorization.

8521531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5932.

The product of its digits is 1200, while the sum is 25.

The square root of 8521531 is about 2919.1661480635. The cubic root of 8521531 is about 204.2549276777.

Adding to 8521531 its reverse (1351258), we get a palindrome (9872789).

The spelling of 8521531 in words is "eight million, five hundred twenty-one thousand, five hundred thirty-one".