21212022121001 has 4 divisors (see below), whose sum is σ = 21230419365972. Its totient is φ = 21193624876032.

The previous prime is 21212022120959. The next prime is 21212022121061. The reversal of 21212022121001 is 10012122021212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13866865182976 + 7345156938025 = 3723824^2 + 2710195^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212022121001 - 2²⁶ = 21211955012137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212022121061) 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, 9198620756 + ... + 9198623061.

It is an arithmetic number, because the mean of its divisors is an integer number (5307604841493).

Almost surely, 2^{21212022121001} is an apocalyptic number.

It is an amenable number.

21212022121001 is a deficient number, since it is larger than the sum of its proper divisors (18397244971).

21212022121001 is a wasteful number, since it uses less digits than its factorization.

21212022121001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18397244970.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21212022121001 its reverse (10012122021212), we get a palindrome (31224144142213).

The spelling of 21212022121001 in words is "twenty-one trillion, two hundred twelve billion, twenty-two million, one hundred twenty-one thousand, one".