21201102001 has 4 divisors (see below), whose sum is σ = 21411014004. Its totient is φ = 20991190000.

The previous prime is 21201101983. The next prime is 21201102011. The reversal of 21201102001 is 10020110212.

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 12504606976 + 8696495025 = 111824^2 + 93255^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201102001 - 2²⁷ = 21066884273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201102011) 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, 104955850 + ... + 104956051.

It is an arithmetic number, because the mean of its divisors is an integer number (5352753501).

Almost surely, 2^21201102001 is an apocalyptic number.

It is an amenable number.

21201102001 is a deficient number, since it is larger than the sum of its proper divisors (209912003).

21201102001 is a wasteful number, since it uses less digits than its factorization.

21201102001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209912002.

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

Adding to 21201102001 its reverse (10020110212), we get a palindrome (31221212213).

The spelling of 21201102001 in words is "twenty-one billion, two hundred one million, one hundred two thousand, one".