16531213 has 4 divisors (see below), whose sum is σ = 16605568. Its totient is φ = 16456860.

The previous prime is 16531211. The next prime is 16531219. The reversal of 16531213 is 31213561.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16531213 - 2¹ = 16531211 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16531211) 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, 36843 + ... + 37288.

It is an arithmetic number, because the mean of its divisors is an integer number (4151392).

Almost surely, 2^16531213 is an apocalyptic number.

It is an amenable number.

16531213 is a deficient number, since it is larger than the sum of its proper divisors (74355).

16531213 is an equidigital number, since it uses as much as digits as its factorization.

16531213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74354.

The product of its digits is 540, while the sum is 22.

The square root of 16531213 is about 4065.8594417417. The cubic root of 16531213 is about 254.7425981362.

Adding to 16531213 its reverse (31213561), we get a palindrome (47744774).

The spelling of 16531213 in words is "sixteen million, five hundred thirty-one thousand, two hundred thirteen".