21212020001 has 2 divisors, whose sum is σ = 21212020002. Its totient is φ = 21212020000.

The previous prime is 21212019953. The next prime is 21212020007. The reversal of 21212020001 is 10002021212.

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., 11196814225 + 10015205776 = 105815^2 + 100076^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212020001 - 2⁶ = 21212019937 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212020007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606010000 + 10606010001.

It is an arithmetic number, because the mean of its divisors is an integer number (10606010001).

Almost surely, 2^21212020001 is an apocalyptic number.

It is an amenable number.

21212020001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212020001 is an equidigital number, since it uses as much as digits as its factorization.

21212020001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21212020001 its reverse (10002021212), we get a palindrome (31214041213).

The spelling of 21212020001 in words is "twenty-one billion, two hundred twelve million, twenty thousand, one".