10021121021 has 4 divisors (see below), whose sum is σ = 10025760444. Its totient is φ = 10016481600.

The previous prime is 10021121009. The next prime is 10021121029. The reversal of 10021121021 is 12012112001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12012112001 = 13411 ⋅895691.

It can be written as a sum of positive squares in 2 ways, for example, as 7941304996 + 2079816025 = 89114^2 + 45605^2 .

It is a cyclic number.

It is not a de Polignac number, because 10021121021 - 2⁶ = 10021120957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10021120993 and 10021121011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10021121029) 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, 2316470 + ... + 2320791.

It is an arithmetic number, because the mean of its divisors is an integer number (2506440111).

Almost surely, 2^10021121021 is an apocalyptic number.

It is an amenable number.

10021121021 is a deficient number, since it is larger than the sum of its proper divisors (4639423).

10021121021 is an equidigital number, since it uses as much as digits as its factorization.

10021121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4639422.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 10021121021 its reverse (12012112001), we get a palindrome (22033233022).

The spelling of 10021121021 in words is "ten billion, twenty-one million, one hundred twenty-one thousand, twenty-one".