16820213 has 4 divisors (see below), whose sum is σ = 16860588. Its totient is φ = 16779840.

The previous prime is 16820189. The next prime is 16820233. The reversal of 16820213 is 31202861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31202861 = 643 ⋅48527.

It can be written as a sum of positive squares in 2 ways, for example, as 4695889 + 12124324 = 2167^2 + 3482^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16820213 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 (16820233) 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, 19556 + ... + 20397.

It is an arithmetic number, because the mean of its divisors is an integer number (4215147).

Almost surely, 2^16820213 is an apocalyptic number.

It is an amenable number.

16820213 is a deficient number, since it is larger than the sum of its proper divisors (40375).

16820213 is an equidigital number, since it uses as much as digits as its factorization.

16820213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40374.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 16820213 is about 4101.2452986867. The cubic root of 16820213 is about 256.2185074921.

The spelling of 16820213 in words is "sixteen million, eight hundred twenty thousand, two hundred thirteen".