221121012021 has 32 divisors (see below), whose sum is σ = 367976060928. Its totient is φ = 114992498880.

The previous prime is 221121012011. The next prime is 221121012023. The reversal of 221121012021 is 120210121122.

It is not a de Polignac number, because 221121012021 - 2¹⁰ = 221121010997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121012023) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 5684611 + ... + 5723376.

It is an arithmetic number, because the mean of its divisors is an integer number (11499251904).

Almost surely, 2^221121012021 is an apocalyptic number.

221121012021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221121012021 is a deficient number, since it is larger than the sum of its proper divisors (146855048907).

221121012021 is a wasteful number, since it uses less digits than its factorization.

221121012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11408081.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 221121012021 its reverse (120210121122), we get a palindrome (341331133143).

The spelling of 221121012021 in words is "two hundred twenty-one billion, one hundred twenty-one million, twelve thousand, twenty-one".