221012021021 has 4 divisors (see below), whose sum is σ = 241104022944. Its totient is φ = 200920019100.

The previous prime is 221012020981. The next prime is 221012021033. The reversal of 221012021021 is 120120210122.

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 a de Polignac number, because none of the positive numbers 2^k-221012021021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221012020987 and 221012021005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221012021071) 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, 10046000945 + ... + 10046000966.

It is an arithmetic number, because the mean of its divisors is an integer number (60276005736).

Almost surely, 2^221012021021 is an apocalyptic number.

It is an amenable number.

221012021021 is a deficient number, since it is larger than the sum of its proper divisors (20092001923).

221012021021 is a wasteful number, since it uses less digits than its factorization.

221012021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20092001922.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 221012021021 its reverse (120120210122), we get a palindrome (341132231143).

The spelling of 221012021021 in words is "two hundred twenty-one billion, twelve million, twenty-one thousand, twenty-one".