221011021 has 32 divisors (see below), whose sum is σ = 296064000. Its totient is φ = 163099440.

The previous prime is 221010971. The next prime is 221011057. The reversal of 221011021 is 120110122.

221011021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-221011021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221010989 and 221011007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221011081) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 70146 + ... + 73228.

It is an arithmetic number, because the mean of its divisors is an integer number (9252000).

Almost surely, 2^221011021 is an apocalyptic number.

It is an amenable number.

221011021 is a deficient number, since it is larger than the sum of its proper divisors (75052979).

221011021 is a wasteful number, since it uses less digits than its factorization.

221011021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3134 (or 3120 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 221011021 is about 14866.4394190405. The cubic root of 221011021 is about 604.6044095615.

Adding to 221011021 its reverse (120110122), we get a palindrome (341121143).

It can be divided in two parts, 2210 and 11021, that added together give a palindrome (13231).

The spelling of 221011021 in words is "two hundred twenty-one million, eleven thousand, twenty-one".