21011001100021 has 16 divisors (see below), whose sum is σ = 22583462198400. Its totient is φ = 19489182536448.

The previous prime is 21011001099997. The next prime is 21011001100027. The reversal of 21011001100021 is 12000110011012.

It is a cyclic number.

It is not a de Polignac number, because 21011001100021 - 2²¹ = 21010999002869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21011001099980 and 21011001100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011001100027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55096561 + ... + 55476598.

It is an arithmetic number, because the mean of its divisors is an integer number (1411466387400).

Almost surely, 2^{21011001100021} is an apocalyptic number.

It is an amenable number.

21011001100021 is a deficient number, since it is larger than the sum of its proper divisors (1572461098379).

21011001100021 is a wasteful number, since it uses less digits than its factorization.

21011001100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110573388.

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

Adding to 21011001100021 its reverse (12000110011012), we get a palindrome (33011111111033).

The spelling of 21011001100021 in words is "twenty-one trillion, eleven billion, one million, one hundred thousand, twenty-one".