820861200208 has 30 divisors (see below), whose sum is σ = 1850078752746. Its totient is φ = 351797656896.

The previous prime is 820861200161. The next prime is 820861200233. The reversal of 820861200208 is 802002168028.

It can be written as a sum of positive squares in only one way, i.e., 420744227904 + 400116972304 = 648648^2 + 632548^2 .

It is a super-2 number, since 2×820861200208² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 523507635 + ... + 523509202.

Almost surely, 2^820861200208 is an apocalyptic number.

It is an amenable number.

820861200208 is an abundant number, since it is smaller than the sum of its proper divisors (1029217552538).

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

820861200208 is a wasteful number, since it uses less digits than its factorization.

820861200208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1047016859 (or 1047016846 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 37.

The spelling of 820861200208 in words is "eight hundred twenty billion, eight hundred sixty-one million, two hundred thousand, two hundred eight".