221144557765 has 8 divisors (see below), whose sum is σ = 266430735648. Its totient is φ = 176210802000.

The previous prime is 221144557763. The next prime is 221144557771. The reversal of 221144557765 is 567755441122.

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

It is not a de Polignac number, because 221144557765 - 2¹ = 221144557763 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221144557763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88104147 + ... + 88106656.

It is an arithmetic number, because the mean of its divisors is an integer number (33303841956).

Almost surely, 2^221144557765 is an apocalyptic number.

It is an amenable number.

221144557765 is a deficient number, since it is larger than the sum of its proper divisors (45286177883).

221144557765 is a wasteful number, since it uses less digits than its factorization.

221144557765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176211059.

The product of its digits is 2352000, while the sum is 49.

Adding to 221144557765 its reverse (567755441122), we get a palindrome (788899998887).

The spelling of 221144557765 in words is "two hundred twenty-one billion, one hundred forty-four million, five hundred fifty-seven thousand, seven hundred sixty-five".