201121220021021 has 4 divisors (see below), whose sum is σ = 201121392070272. Its totient is φ = 201121047971772.

The previous prime is 201121220020997. The next prime is 201121220021023. The reversal of 201121220021021 is 120120022121102.

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 201121220021021 - 2¹⁴ = 201121220004637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201121220021023) 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, 84259085 + ... + 86613138.

It is an arithmetic number, because the mean of its divisors is an integer number (50280348017568).

Almost surely, 2^{201121220021021} is an apocalyptic number.

It is an amenable number.

201121220021021 is a deficient number, since it is larger than the sum of its proper divisors (172049251).

201121220021021 is a wasteful number, since it uses less digits than its factorization.

201121220021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172049250.

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

Adding to 201121220021021 its reverse (120120022121102), we get a palindrome (321241242142123).

The spelling of 201121220021021 in words is "two hundred one trillion, one hundred twenty-one billion, two hundred twenty million, twenty-one thousand, twenty-one".