221400256 has 56 divisors (see below), whose sum is σ = 547762176. Its totient is φ = 86257920.

The previous prime is 221400253. The next prime is 221400307. The reversal of 221400256 is 652004122.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221400253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17536 + ... + 27391.

Almost surely, 2^221400256 is an apocalyptic number.

It is an amenable number.

221400256 is an abundant number, since it is smaller than the sum of its proper divisors (326361920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221400256 is a wasteful number, since it uses less digits than its factorization.

221400256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44957 (or 44947 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 221400256 is about 14879.5247235925. The cubic root of 221400256 is about 604.9591357323.

Adding to 221400256 its reverse (652004122), we get a palindrome (873404378).

The spelling of 221400256 in words is "two hundred twenty-one million, four hundred thousand, two hundred fifty-six".