123221220021 has 12 divisors (see below), whose sum is σ = 178069756800. Its totient is φ = 82108918440.

The previous prime is 123221220019. The next prime is 123221220091. The reversal of 123221220021 is 120022122321.

123221220021 is a `hidden beast` number, since 1 + 232 + 212 + 200 + 21 = 666.

It is not a de Polignac number, because 123221220021 - 2¹ = 123221220019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 123221219976 and 123221220003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123221220091) 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 11 ways as a sum of consecutive naturals, for example, 3193221 + ... + 3231578.

It is an arithmetic number, because the mean of its divisors is an integer number (14839146400).

Almost surely, 2^123221220021 is an apocalyptic number.

It is an amenable number.

123221220021 is a deficient number, since it is larger than the sum of its proper divisors (54848536779).

123221220021 is a wasteful number, since it uses less digits than its factorization.

123221220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6426936 (or 6426933 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 123221220021 its reverse (120022122321), we get a palindrome (243243342342).

The spelling of 123221220021 in words is "one hundred twenty-three billion, two hundred twenty-one million, two hundred twenty thousand, twenty-one".