21100012020001 has 4 divisors (see below), whose sum is σ = 21109867235604. Its totient is φ = 21090156804400.

The previous prime is 21100012019981. The next prime is 21100012020079. The reversal of 21100012020001 is 10002021000112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9159393549601 + 11940618470400 = 3026449^2 + 3455520^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100012020001 - 2⁵ = 21100012019969 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21100012020001.

It is not an unprimeable number, because it can be changed into a prime (21100012020301) 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 3 ways as a sum of consecutive naturals, for example, 4927604590 + ... + 4927608871.

It is an arithmetic number, because the mean of its divisors is an integer number (5277466808901).

Almost surely, 2^{21100012020001} is an apocalyptic number.

It is an amenable number.

21100012020001 is a deficient number, since it is larger than the sum of its proper divisors (9855215603).

21100012020001 is an equidigital number, since it uses as much as digits as its factorization.

21100012020001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9855215602.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21100012020001 its reverse (10002021000112), we get a palindrome (31102033020113).

The spelling of 21100012020001 in words is "twenty-one trillion, one hundred billion, twelve million, twenty thousand, one".