221221221320001 has 24 divisors (see below), whose sum is σ = 346449877834944. Its totient is φ = 125184824261280.

The previous prime is 221221221319999. The next prime is 221221221320039. The reversal of 221221221320001 is 100023122122122.

It is not a de Polignac number, because 221221221320001 - 2¹ = 221221221319999 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 221221221320001.

It is not an unprimeable number, because it can be changed into a prime (221221221322001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7305355090 + ... + 7305385371.

It is an arithmetic number, because the mean of its divisors is an integer number (14435411576456).

Almost surely, 2^{221221221320001} is an apocalyptic number.

221221221320001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221221221320001 is a deficient number, since it is larger than the sum of its proper divisors (125228656514943).

221221221320001 is a wasteful number, since it uses less digits than its factorization.

221221221320001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14610740581 (or 14610740574 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 221221221320001 its reverse (100023122122122), we get a palindrome (321244343442123).

The spelling of 221221221320001 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, two hundred twenty-one million, three hundred twenty thousand, one".