210001210000021 has 16 divisors (see below), whose sum is σ = 241666095490560. Its totient is φ = 180475000631280.

The previous prime is 210001210000013. The next prime is 210001210000039. The reversal of 210001210000021 is 120000012100012.

It is a cyclic number.

It is not a de Polignac number, because 210001210000021 - 2³ = 210001210000013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210001209999962 and 210001210000007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210001210000921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1075695201 + ... + 1075890406.

It is an arithmetic number, because the mean of its divisors is an integer number (15104130968160).

Almost surely, 2^{210001210000021} is an apocalyptic number.

It is an amenable number.

210001210000021 is a deficient number, since it is larger than the sum of its proper divisors (31664885490539).

210001210000021 is a wasteful number, since it uses less digits than its factorization.

210001210000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2151586104.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 210001210000021 its reverse (120000012100012), we get a palindrome (330001222100033).

The spelling of 210001210000021 in words is "two hundred ten trillion, one billion, two hundred ten million, twenty-one", and thus it is an aban number.