821716868196 has 243 divisors, whose sum is σ = 2450640989433. Its totient is φ = 231480264960.

The previous prime is 821716868179. The next prime is 821716868213. The reversal of 821716868196 is 691868617128.

The square root of 821716868196 is 906486.

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

It is an interprime number because it is at equal distance from previous prime (821716868179) and next prime (821716868213).

It can be written as a sum of positive squares in only one way, i.e., 14479308900 + 807237559296 = 120330^2 + 898464^2 .

It is a super-2 number, since 2×821716868196² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 4302182461 + ... + 4302182651.

Almost surely, 2^821716868196 is an apocalyptic number.

821716868196 is the 906486-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821716868196

821716868196 is an abundant number, since it is smaller than the sum of its proper divisors (1628924121237).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821716868196 is a wasteful number, since it uses less digits than its factorization.

821716868196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632 (or 316 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 63.

The spelling of 821716868196 in words is "eight hundred twenty-one billion, seven hundred sixteen million, eight hundred sixty-eight thousand, one hundred ninety-six".