21211112201 has 2 divisors, whose sum is σ = 21211112202. Its totient is φ = 21211112200.

The previous prime is 21211112191. The next prime is 21211112207. The reversal of 21211112201 is 10221111212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16199180176 + 5011932025 = 127276^2 + 70795^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211112201 is a prime.

It is a super-2 number, since 2×21211112201² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21211112207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605556100 + 10605556101.

It is an arithmetic number, because the mean of its divisors is an integer number (10605556101).

Almost surely, 2^21211112201 is an apocalyptic number.

It is an amenable number.

21211112201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211112201 is an equidigital number, since it uses as much as digits as its factorization.

21211112201 is an evil number, because the sum of its binary digits is even.

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

Adding to 21211112201 its reverse (10221111212), we get a palindrome (31432223413).

The spelling of 21211112201 in words is "twenty-one billion, two hundred eleven million, one hundred twelve thousand, two hundred one".