820221002021200 has 120 divisors (see below), whose sum is σ = 2173924208680056. Its totient is φ = 295464225792000.

The previous prime is 820221002021191. The next prime is 820221002021273. The reversal of 820221002021200 is 2120200122028.

It can be written as a sum of positive squares in 12 ways, for example, as 678467880277056 + 141753121744144 = 26047416^2 + 11906012^2 .

It is a super-2 number, since 2×820221002021200² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1923382021 + ... + 1923808420.

Almost surely, 2^{820221002021200} is an apocalyptic number.

820221002021200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

820221002021200 is an abundant number, since it is smaller than the sum of its proper divisors (1353703206658856).

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

820221002021200 is a wasteful number, since it uses less digits than its factorization.

820221002021200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3847190513 (or 3847190502 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

Adding to 820221002021200 its reverse (2120200122028), we get a palindrome (822341202143228).

The spelling of 820221002021200 in words is "eight hundred twenty trillion, two hundred twenty-one billion, two million, twenty-one thousand, two hundred".