21004141021 has 4 divisors (see below), whose sum is σ = 21004824544. Its totient is φ = 21003457500.

The previous prime is 21004141013. The next prime is 21004141031. The reversal of 21004141021 is 12014140012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21004141021 - 2³ = 21004141013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21004140986 and 21004141004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004141001) 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, 293385 + ... + 357886.

It is an arithmetic number, because the mean of its divisors is an integer number (5251206136).

Almost surely, 2^21004141021 is an apocalyptic number.

It is an amenable number.

21004141021 is a deficient number, since it is larger than the sum of its proper divisors (683523).

21004141021 is an equidigital number, since it uses as much as digits as its factorization.

21004141021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683522.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21004141021 its reverse (12014140012), we get a palindrome (33018281033).

The spelling of 21004141021 in words is "twenty-one billion, four million, one hundred forty-one thousand, twenty-one".