100001200021 has 4 divisors (see below), whose sum is σ = 101124809100. Its totient is φ = 98877590944.

The previous prime is 100001199979. The next prime is 100001200031. The reversal of 100001200021 is 120002100001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 45016108900 + 54985091121 = 212170^2 + 234489^2 .

It is a cyclic number.

It is not a de Polignac number, because 100001200021 - 2²⁹ = 99464329109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100001199977 and 100001200013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100001200031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 561804406 + ... + 561804583.

It is an arithmetic number, because the mean of its divisors is an integer number (25281202275).

Almost surely, 2^100001200021 is an apocalyptic number.

It is an amenable number.

100001200021 is a deficient number, since it is larger than the sum of its proper divisors (1123609079).

100001200021 is an equidigital number, since it uses as much as digits as its factorization.

100001200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1123609078.

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 100001200021 its reverse (120002100001), we get a palindrome (220003300022).

The spelling of 100001200021 in words is "one hundred billion, one million, two hundred thousand, twenty-one".