21000021000101 has 32 divisors (see below), whose sum is σ = 24917033998080. Its totient is φ = 17446928832000.

The previous prime is 21000021000089. The next prime is 21000021000121. The reversal of 21000021000101 is 10100012000012.

It is a cyclic number.

It is not a de Polignac number, because 21000021000101 - 2¹⁸ = 21000020737957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000021000121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 371200145 + ... + 371256713.

It is an arithmetic number, because the mean of its divisors is an integer number (778657312440).

Almost surely, 2^{21000021000101} is an apocalyptic number.

It is an amenable number.

21000021000101 is a deficient number, since it is larger than the sum of its proper divisors (3917012997979).

21000021000101 is a wasteful number, since it uses less digits than its factorization.

21000021000101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82397.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21000021000101 its reverse (10100012000012), we get a palindrome (31100033000113).

The spelling of 21000021000101 in words is "twenty-one trillion, twenty-one million, one hundred one", and thus it is an aban number.