21211101001 has 4 divisors (see below), whose sum is σ = 21421112004. Its totient is φ = 21001090000.

The previous prime is 21211100993. The next prime is 21211101029. The reversal of 21211101001 is 10010111212.

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 16745654025 + 4465446976 = 129405^2 + 66824^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211101001 - 2³ = 21211100993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211104001) 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, 105005350 + ... + 105005551.

It is an arithmetic number, because the mean of its divisors is an integer number (5355278001).

Almost surely, 2^21211101001 is an apocalyptic number.

It is an amenable number.

21211101001 is a deficient number, since it is larger than the sum of its proper divisors (210011003).

21211101001 is a wasteful number, since it uses less digits than its factorization.

21211101001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210011002.

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

Adding to 21211101001 its reverse (10010111212), we get a palindrome (31221212213).

The spelling of 21211101001 in words is "twenty-one billion, two hundred eleven million, one hundred one thousand, one".