201221002121004 has 18 divisors (see below), whose sum is σ = 508641977583740. Its totient is φ = 67073667373656.

The previous prime is 201221002120939. The next prime is 201221002121011. The reversal of 201221002121004 is 400121200122102.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2794736140534 + ... + 2794736140605.

Almost surely, 2^{201221002121004} is an apocalyptic number.

It is an amenable number.

201221002121004 is an abundant number, since it is smaller than the sum of its proper divisors (307420975462736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

201221002121004 is a wasteful number, since it uses less digits than its factorization.

201221002121004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5589472281149 (or 5589472281144 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 201221002121004 its reverse (400121200122102), we get a palindrome (601342202243106).

The spelling of 201221002121004 in words is "two hundred one trillion, two hundred twenty-one billion, two million, one hundred twenty-one thousand, four".