21011002001021 has 8 divisors (see below), whose sum is σ = 21200476701600. Its totient is φ = 20822265994032.

The previous prime is 21011002000979. The next prime is 21011002001023. The reversal of 21011002001021 is 12010020011012.

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 21011002001021 - 2⁶ = 21011002000957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011002000993 and 21011002001011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011002001023) 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, 184616255 + ... + 184730028.

It is an arithmetic number, because the mean of its divisors is an integer number (2650059587700).

Almost surely, 2^{21011002001021} is an apocalyptic number.

It is an amenable number.

21011002001021 is a deficient number, since it is larger than the sum of its proper divisors (189474700579).

21011002001021 is a wasteful number, since it uses less digits than its factorization.

21011002001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369346795.

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

Adding to 21011002001021 its reverse (12010020011012), we get a palindrome (33021022012033).

The spelling of 21011002001021 in words is "twenty-one trillion, eleven billion, two million, one thousand, twenty-one".