21000011101021 has 8 divisors (see below), whose sum is σ = 22105426324320. Its totient is φ = 19894611025872.

The previous prime is 21000011100997. The next prime is 21000011101051. The reversal of 21000011101021 is 12010111000012.

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 21000011101021 - 2¹⁹ = 21000010576733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000011100989 and 21000011101007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000011101051) 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, 884395 + ... + 6540808.

It is an arithmetic number, because the mean of its divisors is an integer number (2763178290540).

Almost surely, 2^{21000011101021} is an apocalyptic number.

It is an amenable number.

21000011101021 is a deficient number, since it is larger than the sum of its proper divisors (1105415223299).

21000011101021 is a wasteful number, since it uses less digits than its factorization.

21000011101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7574075.

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

Adding to 21000011101021 its reverse (12010111000012), we get a palindrome (33010122101033).

The spelling of 21000011101021 in words is "twenty-one trillion, eleven million, one hundred one thousand, twenty-one".