1000021000100 has 72 divisors (see below), whose sum is σ = 2223543783048. Its totient is φ = 390151987200.

The previous prime is 1000021000079. The next prime is 1000021000103. The reversal of 1000021000100 is 10001200001.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 419937696676 + 580083303424 = 648026^2 + 761632^2 .

It is a Harshad number since it is a multiple of its sum of digits (5).

It is not an unprimeable number, because it can be changed into a prime (1000021000103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17096504 + ... + 17154896.

Almost surely, 2^{1000021000100} is an apocalyptic number.

1000021000100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1000021000100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1111771891524).

1000021000100 is an abundant number, since it is smaller than the sum of its proper divisors (1223522782948).

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

1000021000100 is a wasteful number, since it uses less digits than its factorization.

1000021000100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62625 (or 62618 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 5.

Adding to 1000021000100 its reverse (10001200001), we get a palindrome (1010022200101).

The spelling of 1000021000100 in words is "one trillion, twenty-one million, one hundred", and thus it is an aban number.