221664121072 has 40 divisors (see below), whose sum is σ = 452272706960. Its totient is φ = 104953605120.

The previous prime is 221664121051. The next prime is 221664121093. The reversal of 221664121072 is 270121466122.

It is an interprime number because it is at equal distance from previous prime (221664121051) and next prime (221664121093).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 555928 + ... + 867400.

It is an arithmetic number, because the mean of its divisors is an integer number (11306817674).

Almost surely, 2^221664121072 is an apocalyptic number.

It is an amenable number.

221664121072 is an abundant number, since it is smaller than the sum of its proper divisors (230608585888).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221664121072 is a wasteful number, since it uses less digits than its factorization.

221664121072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313841 (or 313835 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

Adding to 221664121072 its reverse (270121466122), we get a palindrome (491785587194).

The spelling of 221664121072 in words is "two hundred twenty-one billion, six hundred sixty-four million, one hundred twenty-one thousand, seventy-two".