816553213 has 4 divisors (see below), whose sum is σ = 933203680. Its totient is φ = 699902748.

The previous prime is 816553193. The next prime is 816553223. The reversal of 816553213 is 312355618.

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, and also an emirpimes, since its reverse is a distinct semiprime: 312355618 = 2 ⋅156177809.

It is a cyclic number.

It is not a de Polignac number, because 816553213 - 2⁹ = 816552701 is a prime.

It is a super-3 number, since 3×816553213³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816553223) 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, 58325223 + ... + 58325236.

It is an arithmetic number, because the mean of its divisors is an integer number (233300920).

Almost surely, 2^816553213 is an apocalyptic number.

It is an amenable number.

816553213 is a deficient number, since it is larger than the sum of its proper divisors (116650467).

816553213 is a wasteful number, since it uses less digits than its factorization.

816553213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116650466.

The product of its digits is 21600, while the sum is 34.

The square root of 816553213 is about 28575.3952378615. The cubic root of 816553213 is about 934.6768738644.

The spelling of 816553213 in words is "eight hundred sixteen million, five hundred fifty-three thousand, two hundred thirteen".