21021101021 has 8 divisors (see below), whose sum is σ = 21630384384. Its totient is φ = 20416416480.

The previous prime is 21021100987. The next prime is 21021101051. The reversal of 21021101021 is 12010112012.

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 21021101021 - 2³⁰ = 19947359197 is a prime.

It is a super-3 number, since 3×21021101021³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21021100993 and 21021101011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021101051) 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, 1140431 + ... + 1158716.

It is an arithmetic number, because the mean of its divisors is an integer number (2703798048).

Almost surely, 2^21021101021 is an apocalyptic number.

It is an amenable number.

21021101021 is a deficient number, since it is larger than the sum of its proper divisors (609283363).

21021101021 is a wasteful number, since it uses less digits than its factorization.

21021101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2299411.

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

Adding to 21021101021 its reverse (12010112012), we get a palindrome (33031213033).

The spelling of 21021101021 in words is "twenty-one billion, twenty-one million, one hundred one thousand, twenty-one".