21211211010001 has 2 divisors, whose sum is σ = 21211211010002. Its totient is φ = 21211211010000.

The previous prime is 21211211009909. The next prime is 21211211010047. The reversal of 21211211010001 is 10001011211212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14395012693776 + 6816198316225 = 3794076^2 + 2610785^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211211010001 - 2⁷ = 21211211009873 is a prime.

It is not a weakly prime, because it can be changed into another prime (21211211010091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605605505000 + 10605605505001.

It is an arithmetic number, because the mean of its divisors is an integer number (10605605505001).

Almost surely, 2^{21211211010001} is an apocalyptic number.

It is an amenable number.

21211211010001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211211010001 is an equidigital number, since it uses as much as digits as its factorization.

21211211010001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21211211010001 its reverse (10001011211212), we get a palindrome (31212222221213).

The spelling of 21211211010001 in words is "twenty-one trillion, two hundred eleven billion, two hundred eleven million, ten thousand, one".