10021111021 has 4 divisors (see below), whose sum is σ = 10120330044. Its totient is φ = 9921892000.

The previous prime is 10021111019. The next prime is 10021111103. The reversal of 10021111021 is 12011112001.

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 8333133796 + 1687977225 = 91286^2 + 41085^2 .

It is a cyclic number.

It is not a de Polignac number, because 10021111021 - 2¹ = 10021111019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10021110989 and 10021111007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10021111621) 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, 49609360 + ... + 49609561.

It is an arithmetic number, because the mean of its divisors is an integer number (2530082511).

Almost surely, 2^10021111021 is an apocalyptic number.

It is an amenable number.

10021111021 is a deficient number, since it is larger than the sum of its proper divisors (99219023).

10021111021 is an equidigital number, since it uses as much as digits as its factorization.

10021111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99219022.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 10021111021 its reverse (12011112001), we get a palindrome (22032223022).

The spelling of 10021111021 in words is "ten billion, twenty-one million, one hundred eleven thousand, twenty-one".