21010021000101 has 24 divisors (see below), whose sum is σ = 34725351772800. Its totient is φ = 11991138496416.

The previous prime is 21010021000079. The next prime is 21010021000121. The reversal of 21010021000101 is 10100012001012.

It is a happy number.

It is not a de Polignac number, because 21010021000101 - 2¹¹ = 21010020998053 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010021000121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 202555926 + ... + 202659623.

It is an arithmetic number, because the mean of its divisors is an integer number (1446889657200).

Almost surely, 2^{21010021000101} is an apocalyptic number.

21010021000101 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21010021000101 is a deficient number, since it is larger than the sum of its proper divisors (13715330772699).

21010021000101 is a wasteful number, since it uses less digits than its factorization.

21010021000101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405216385 (or 405216382 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21010021000101 its reverse (10100012001012), we get a palindrome (31110033001113).

The spelling of 21010021000101 in words is "twenty-one trillion, ten billion, twenty-one million, one hundred one", and thus it is an aban number.