816640853 has 16 divisors (see below), whose sum is σ = 955516416. Its totient is φ = 683510400.

The previous prime is 816640837. The next prime is 816640859. The reversal of 816640853 is 358046618.

It is a cyclic number.

It is not a de Polignac number, because 816640853 - 2⁴ = 816640837 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 816640853.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816640859) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43700 + ... + 59522.

It is an arithmetic number, because the mean of its divisors is an integer number (59719776).

Almost surely, 2^816640853 is an apocalyptic number.

It is an amenable number.

816640853 is a deficient number, since it is larger than the sum of its proper divisors (138875563).

816640853 is a wasteful number, since it uses less digits than its factorization.

816640853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16004.

The product of its (nonzero) digits is 138240, while the sum is 41.

The square root of 816640853 is about 28576.9286838177. The cubic root of 816640853 is about 934.7103120406.

The spelling of 816640853 in words is "eight hundred sixteen million, six hundred forty thousand, eight hundred fifty-three".