1021110100020 has 72 divisors (see below), whose sum is σ = 3104520813576. Its totient is φ = 271667146752.

The previous prime is 1021110100009. The next prime is 1021110100037. The reversal of 1021110100020 is 200010111201.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 49521381156 + 971588718864 = 222534^2 + 985692^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 1021110099975 and 1021110100011.

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 23 ways as a sum of consecutive naturals, for example, 6472677 + ... + 6628556.

It is an arithmetic number, because the mean of its divisors is an integer number (43118344633).

Almost surely, 2^{1021110100020} is an apocalyptic number.

1021110100020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021110100020 is an abundant number, since it is smaller than the sum of its proper divisors (2083410713556).

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

1021110100020 is a wasteful number, since it uses less digits than its factorization.

1021110100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13101681 (or 13101676 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 1021110100020 its reverse (200010111201), we get a palindrome (1221120211221).

The spelling of 1021110100020 in words is "one trillion, twenty-one billion, one hundred ten million, one hundred thousand, twenty".