21101100001 has 4 divisors (see below), whose sum is σ = 21112367812. Its totient is φ = 21089832192.

The previous prime is 21101099989. The next prime is 21101100061. The reversal of 21101100001 is 10000110112.

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 6137939025 + 14963160976 = 78345^2 + 122324^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101100001 - 2¹⁷ = 21100968929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101100061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5631096 + ... + 5634841.

It is an arithmetic number, because the mean of its divisors is an integer number (5278091953).

Almost surely, 2^21101100001 is an apocalyptic number.

It is an amenable number.

21101100001 is a deficient number, since it is larger than the sum of its proper divisors (11267811).

21101100001 is a wasteful number, since it uses less digits than its factorization.

21101100001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11267810.

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 21101100001 its reverse (10000110112), we get a palindrome (31101210113).

The spelling of 21101100001 in words is "twenty-one billion, one hundred one million, one hundred thousand, one".