221800655 has 8 divisors (see below), whose sum is σ = 267948000. Its totient is φ = 176249056.

The previous prime is 221800633. The next prime is 221800679. The reversal of 221800655 is 556008122.

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 221800655 - 2⁶ = 221800591 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 148115 + ... + 149604.

It is an arithmetic number, because the mean of its divisors is an integer number (33493500).

Almost surely, 2^221800655 is an apocalyptic number.

221800655 is a deficient number, since it is larger than the sum of its proper divisors (46147345).

221800655 is a wasteful number, since it uses less digits than its factorization.

221800655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297873.

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 221800655 is about 14892.9733431575. The cubic root of 221800655 is about 605.3236025789.

Adding to 221800655 its reverse (556008122), we get a palindrome (777808777).

The spelling of 221800655 in words is "two hundred twenty-one million, eight hundred thousand, six hundred fifty-five".