21211211201 has 8 divisors (see below), whose sum is σ = 21562713480. Its totient is φ = 20861356032.

The previous prime is 21211211191. The next prime is 21211211207. The reversal of 21211211201 is 10211211212.

It can be written as a sum of positive squares in 4 ways, for example, as 201601 + 21211009600 = 449^2 + 145640^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21211211201 - 2¹⁴ = 21211194817 is a prime.

It is a super-2 number, since 2×21211211201² (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 (21211211207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 385796 + ... + 437333.

It is an arithmetic number, because the mean of its divisors is an integer number (2695339185).

Almost surely, 2^21211211201 is an apocalyptic number.

It is an amenable number.

21211211201 is a deficient number, since it is larger than the sum of its proper divisors (351502279).

21211211201 is an equidigital number, since it uses as much as digits as its factorization.

21211211201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 823555.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21211211201 its reverse (10211211212), we get a palindrome (31422422413).

The spelling of 21211211201 in words is "twenty-one billion, two hundred eleven million, two hundred eleven thousand, two hundred one".