16520531 has 4 divisors (see below), whose sum is σ = 16800600. Its totient is φ = 16240464.

The previous prime is 16520527. The next prime is 16520561. The reversal of 16520531 is 13502561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16520531 - 2² = 16520527 is a prime.

It is a super-2 number, since 2×16520531² = 545855889043922, 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 = 16520497 and 16520506.

It is not an unprimeable number, because it can be changed into a prime (16520521) 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 in 3 ways as a sum of consecutive naturals, for example, 139946 + ... + 140063.

It is an arithmetic number, because the mean of its divisors is an integer number (4200150).

Almost surely, 2^16520531 is an apocalyptic number.

16520531 is a deficient number, since it is larger than the sum of its proper divisors (280069).

16520531 is an equidigital number, since it uses as much as digits as its factorization.

16520531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280068.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 16520531 is about 4064.5456080600. The cubic root of 16520531 is about 254.6877171715.

The spelling of 16520531 in words is "sixteen million, five hundred twenty thousand, five hundred thirty-one".