8216185899321 has 81 divisors (see below), whose sum is σ = 12576189681133. Its totient is φ = 5168672644800.

The previous prime is 8216185899319. The next prime is 8216185899359. The reversal of 8216185899321 is 1239985816128.

The square root of 8216185899321 is 2866389.

It is a perfect power (a square), and thus also a powerful number.

8216185899321 is a `hidden beast` number, since 8 + 2 + 1 + 6 + 18 + 589 + 9 + 32 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1426617636921 + 6789568262400 = 1194411^2 + 2605680^2 .

It is not a de Polignac number, because 8216185899321 - 2¹ = 8216185899319 is a prime.

It is a super-2 number, since 2×8216185899321² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8216185894321) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 11720664271 + ... + 11720664971.

Almost surely, 2^{8216185899321} is an apocalyptic number.

8216185899321 is the 2866389-th square number.

8216185899321 is the 1433195-th centered octagonal number.

It is an amenable number.

8216185899321 is a deficient number, since it is larger than the sum of its proper divisors (4360003781812).

8216185899321 is an frugal number, since it uses more digits than its factorization.

8216185899321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1560 (or 780 counting only the distinct ones).

The product of its digits is 14929920, while the sum is 63.

The spelling of 8216185899321 in words is "eight trillion, two hundred sixteen billion, one hundred eighty-five million, eight hundred ninety-nine thousand, three hundred twenty-one".