221953658561 has 8 divisors (see below), whose sum is σ = 222287143680. Its totient is φ = 221620258512.

The previous prime is 221953658543. The next prime is 221953658593. The reversal of 221953658561 is 165856359122.

221953658561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221953658561 - 2³⁴ = 204773789377 is a prime.

It is a super-2 number, since 2×221953658561² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221953657561) 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 7 ways as a sum of consecutive naturals, for example, 6817520 + ... + 6849998.

It is an arithmetic number, because the mean of its divisors is an integer number (27785892960).

Almost surely, 2^221953658561 is an apocalyptic number.

It is an amenable number.

221953658561 is a deficient number, since it is larger than the sum of its proper divisors (333485119).

221953658561 is an equidigital number, since it uses as much as digits as its factorization.

221953658561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42535.

The product of its digits is 3888000, while the sum is 53.

The spelling of 221953658561 in words is "two hundred twenty-one billion, nine hundred fifty-three million, six hundred fifty-eight thousand, five hundred sixty-one".