21211311001 has 4 divisors (see below), whose sum is σ = 21278223972. Its totient is φ = 21144398032.

The previous prime is 21211310951. The next prime is 21211311013. The reversal of 21211311001 is 10011311212.

It is a happy number.

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 1150837776 + 20060473225 = 33924^2 + 141635^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211311001 - 2⁹ = 21211310489 is a prime.

It is a super-2 number, since 2×21211311001² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211311041) 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, 33456010 + ... + 33456643.

It is an arithmetic number, because the mean of its divisors is an integer number (5319555993).

Almost surely, 2^21211311001 is an apocalyptic number.

It is an amenable number.

21211311001 is a deficient number, since it is larger than the sum of its proper divisors (66912971).

21211311001 is an equidigital number, since it uses as much as digits as its factorization.

21211311001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66912970.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21211311001 its reverse (10011311212), we get a palindrome (31222622213).

The spelling of 21211311001 in words is "twenty-one billion, two hundred eleven million, three hundred eleven thousand, one".