21010010210021 has 16 divisors (see below), whose sum is σ = 24021502525440. Its totient is φ = 18001034362800.

The previous prime is 21010010210003. The next prime is 21010010210023. The reversal of 21010010210021 is 12001201001012.

It is a cyclic number.

It is not a de Polignac number, because 21010010210021 - 2¹⁸ = 21010009947877 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21010010209984 and 21010010210011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010010210023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 408673700 + ... + 408725106.

It is an arithmetic number, because the mean of its divisors is an integer number (1501343907840).

Almost surely, 2^{21010010210021} is an apocalyptic number.

It is an amenable number.

21010010210021 is a deficient number, since it is larger than the sum of its proper divisors (3011492315419).

21010010210021 is a wasteful number, since it uses less digits than its factorization.

21010010210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74744.

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

Adding to 21010010210021 its reverse (12001201001012), we get a palindrome (33011211211033).

The spelling of 21010010210021 in words is "twenty-one trillion, ten billion, ten million, two hundred ten thousand, twenty-one".