20001021022100 has 18 divisors (see below), whose sum is σ = 43402215618174. Its totient is φ = 8000408408800.

The previous prime is 20001021022057. The next prime is 20001021022123. The reversal of 20001021022100 is 122012010002.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 4123441951876 + 15877579070224 = 2030626^2 + 3984668^2 .

It is a super-2 number, since 2×20001021022100² (a number of 27 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 5 ways as a sum of consecutive naturals, for example, 100005105011 + ... + 100005105210.

Almost surely, 2^{20001021022100} is an apocalyptic number.

20001021022100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20001021022100 is an abundant number, since it is smaller than the sum of its proper divisors (23401194596074).

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

20001021022100 is a wasteful number, since it uses less digits than its factorization.

20001021022100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200010210235 (or 200010210228 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20001021022100 its reverse (122012010002), we get a palindrome (20123033032102).

The spelling of 20001021022100 in words is "twenty trillion, one billion, twenty-one million, twenty-two thousand, one hundred".