221609256 has 32 divisors (see below), whose sum is σ = 604389600. Its totient is φ = 67154240.

The previous prime is 221609249. The next prime is 221609257. The reversal of 221609256 is 652906122.

It is a super-2 number, since 2×221609256² = 98221324689747072, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (221609257) 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, 419451 + ... + 419978.

It is an arithmetic number, because the mean of its divisors is an integer number (18887175).

Almost surely, 2^221609256 is an apocalyptic number.

It is an amenable number.

221609256 is an abundant number, since it is smaller than the sum of its proper divisors (382780344).

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

221609256 is a wasteful number, since it uses less digits than its factorization.

221609256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839449 (or 839445 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 221609256 is about 14886.5461407272. The cubic root of 221609256 is about 605.1494346619.

The spelling of 221609256 in words is "two hundred twenty-one million, six hundred nine thousand, two hundred fifty-six".