16413521 has 4 divisors (see below), whose sum is σ = 16424100. Its totient is φ = 16402944.

The previous prime is 16413503. The next prime is 16413541. The reversal of 16413521 is 12531461.

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.

It can be written as a sum of positive squares in 2 ways, for example, as 11730625 + 4682896 = 3425^2 + 2164^2 .

It is a cyclic number.

It is not a de Polignac number, because 16413521 - 2⁶ = 16413457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16413541) 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, 2456 + ... + 6233.

It is an arithmetic number, because the mean of its divisors is an integer number (4106025).

Almost surely, 2^16413521 is an apocalyptic number.

It is an amenable number.

16413521 is a deficient number, since it is larger than the sum of its proper divisors (10579).

16413521 is an equidigital number, since it uses as much as digits as its factorization.

16413521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10578.

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

The square root of 16413521 is about 4051.3603888077. The cubic root of 16413521 is about 254.1366212745.

Adding to 16413521 its reverse (12531461), we get a palindrome (28944982).

The spelling of 16413521 in words is "sixteen million, four hundred thirteen thousand, five hundred twenty-one".