221028855 has 8 divisors (see below), whose sum is σ = 353646192. Its totient is φ = 117882048.

The previous prime is 221028823. The next prime is 221028859. The reversal of 221028855 is 558820122.

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

It is not a de Polignac number, because 221028855 - 2⁵ = 221028823 is a prime.

It is a super-2 number, since 2×221028855² = 97707509485222050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221028859) 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, 7367614 + ... + 7367643.

It is an arithmetic number, because the mean of its divisors is an integer number (44205774).

Almost surely, 2^221028855 is an apocalyptic number.

221028855 is a deficient number, since it is larger than the sum of its proper divisors (132617337).

221028855 is a wasteful number, since it uses less digits than its factorization.

221028855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14735265.

The product of its (nonzero) digits is 12800, while the sum is 33.

The square root of 221028855 is about 14867.0392143157. The cubic root of 221028855 is about 604.6206715334.

Adding to 221028855 its reverse (558820122), we get a palindrome (779848977).

The spelling of 221028855 in words is "two hundred twenty-one million, twenty-eight thousand, eight hundred fifty-five".