221206621973 has 16 divisors (see below), whose sum is σ = 229700889600. Its totient is φ = 212798275200.

The previous prime is 221206621969. The next prime is 221206621981. The reversal of 221206621973 is 379126602122.

It is a cyclic number.

It is not a de Polignac number, because 221206621973 - 2² = 221206621969 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 221206621973.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221206621963) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16023728 + ... + 16037526.

It is an arithmetic number, because the mean of its divisors is an integer number (14356305600).

Almost surely, 2^221206621973 is an apocalyptic number.

It is an amenable number.

221206621973 is a deficient number, since it is larger than the sum of its proper divisors (8494267627).

221206621973 is a wasteful number, since it uses less digits than its factorization.

221206621973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16868.

The product of its (nonzero) digits is 108864, while the sum is 41.

The spelling of 221206621973 in words is "two hundred twenty-one billion, two hundred six million, six hundred twenty-one thousand, nine hundred seventy-three".