100021002021 has 24 divisors (see below), whose sum is σ = 145353080600. Its totient is φ = 66276527616.

The previous prime is 100021002019. The next prime is 100021002031. The reversal of 100021002021 is 120200120001.

It can be written as a sum of positive squares in 4 ways, for example, as 171321921 + 99849680100 = 13089^2 + 315990^2 .

It is not a de Polignac number, because 100021002021 - 2¹ = 100021002019 is a prime.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100021001994 and 100021002012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100021002031) 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, 932265 + ... + 1034001.

Almost surely, 2^100021002021 is an apocalyptic number.

It is an amenable number.

100021002021 is a deficient number, since it is larger than the sum of its proper divisors (45332078579).

100021002021 is a wasteful number, since it uses less digits than its factorization.

100021002021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102405 (or 102402 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 100021002021 its reverse (120200120001), we get a palindrome (220221122022).

The spelling of 100021002021 in words is "one hundred billion, twenty-one million, two thousand, twenty-one".