21012010002121 has 4 divisors (see below), whose sum is σ = 21016203184144. Its totient is φ = 21007816820100.

The previous prime is 21012010002083. The next prime is 21012010002167. The reversal of 21012010002121 is 12120001021012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21012010002121 - 2¹³ = 21012009993929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012010002521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2096583495 + ... + 2096593516.

It is an arithmetic number, because the mean of its divisors is an integer number (5254050796036).

Almost surely, 2^{21012010002121} is an apocalyptic number.

It is an amenable number.

21012010002121 is a deficient number, since it is larger than the sum of its proper divisors (4193182023).

21012010002121 is an equidigital number, since it uses as much as digits as its factorization.

21012010002121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4193182022.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21012010002121 its reverse (12120001021012), we get a palindrome (33132011023133).

The spelling of 21012010002121 in words is "twenty-one trillion, twelve billion, ten million, two thousand, one hundred twenty-one".