221021101110021 has 16 divisors (see below), whose sum is σ = 298687307483136. Its totient is φ = 145362026502576.

The previous prime is 221021101109999. The next prime is 221021101110077. The reversal of 221021101110021 is 120011101120122.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-221021101110021 is a prime.

It is a super-2 number, since 2×221021101110021² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021101110421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1359764065 + ... + 1359926598.

It is an arithmetic number, because the mean of its divisors is an integer number (18667956717696).

Almost surely, 2^{221021101110021} is an apocalyptic number.

It is an amenable number.

221021101110021 is a deficient number, since it is larger than the sum of its proper divisors (77666206373115).

221021101110021 is a wasteful number, since it uses less digits than its factorization.

221021101110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2719691032.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 221021101110021 its reverse (120011101120122), we get a palindrome (341032202230143).

It can be divided in two parts, 221021101 and 110021, that added together give a palindrome (221131122).

The spelling of 221021101110021 in words is "two hundred twenty-one trillion, twenty-one billion, one hundred one million, one hundred ten thousand, twenty-one".