221121321755 has 16 divisors (see below), whose sum is σ = 266049891360. Its totient is φ = 176428069632.

The previous prime is 221121321749. The next prime is 221121321781. The reversal of 221121321755 is 557123121122.

It is a cyclic number.

It is not a de Polignac number, because 221121321755 - 2²⁴ = 221104544539 is a prime.

It is a super-3 number, since 3×221121321755³ (a number of 35 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3272351 + ... + 3339239.

It is an arithmetic number, because the mean of its divisors is an integer number (16628118210).

Almost surely, 2^221121321755 is an apocalyptic number.

221121321755 is a deficient number, since it is larger than the sum of its proper divisors (44928569605).

221121321755 is a wasteful number, since it uses less digits than its factorization.

221121321755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68638.

The product of its digits is 8400, while the sum is 32.

Adding to 221121321755 its reverse (557123121122), we get a palindrome (778244442877).

The spelling of 221121321755 in words is "two hundred twenty-one billion, one hundred twenty-one million, three hundred twenty-one thousand, seven hundred fifty-five".