100001000021 has 8 divisors (see below), whose sum is σ = 110320053144. Its totient is φ = 90057185280.

The previous prime is 100001000017. The next prime is 100001000081. The reversal of 100001000021 is 120000100001.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3179832100 + 96821167921 = 56390^2 + 311161^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 100001000021 - 2² = 100001000017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100000999969 and 100001000014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100001000081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 93809036 + ... + 93810101.

It is an arithmetic number, because the mean of its divisors is an integer number (13790006643).

Almost surely, 2^100001000021 is an apocalyptic number.

It is an amenable number.

100001000021 is a deficient number, since it is larger than the sum of its proper divisors (10319053123).

100001000021 is a wasteful number, since it uses less digits than its factorization.

100001000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187619191.

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

Adding to 100001000021 its reverse (120000100001), we get a palindrome (220001100022).

The spelling of 100001000021 in words is "one hundred billion, one million, twenty-one", and thus it is an aban number.