21210000001 has 2 divisors, whose sum is σ = 21210000002. Its totient is φ = 21210000000.

The previous prime is 21209999977. The next prime is 21210000013. The reversal of 21210000001 is 10000001212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19099516401 + 2110483600 = 138201^2 + 45940^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21210000001 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210000061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605000000 + 10605000001.

It is an arithmetic number, because the mean of its divisors is an integer number (10605000001).

Almost surely, 2^21210000001 is an apocalyptic number.

It is an amenable number.

21210000001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210000001 is an equidigital number, since it uses as much as digits as its factorization.

21210000001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 21210000001 its reverse (10000001212), we get a palindrome (31210001213).

It can be divided in two parts, 212 and 10000001, that multiplied together give a palindrome (2120000212).

The spelling of 21210000001 in words is "twenty-one billion, two hundred ten million, one", and thus it is an aban number.