21210012001 has 2 divisors, whose sum is σ = 21210012002. Its totient is φ = 21210012000.

The previous prime is 21210011993. The next prime is 21210012013. The reversal of 21210012001 is 10021001212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21009053025 + 200958976 = 144945^2 + 14176^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210012001 - 2³ = 21210011993 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210012301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605006000 + 10605006001.

It is an arithmetic number, because the mean of its divisors is an integer number (10605006001).

Almost surely, 2^21210012001 is an apocalyptic number.

It is an amenable number.

21210012001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210012001 is an equidigital number, since it uses as much as digits as its factorization.

21210012001 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 10.

Adding to 21210012001 its reverse (10021001212), we get a palindrome (31231013213).

The spelling of 21210012001 in words is "twenty-one billion, two hundred ten million, twelve thousand, one".