221171956 has 12 divisors (see below), whose sum is σ = 403879392. Its totient is φ = 105777848.

The previous prime is 221171941. The next prime is 221171957. The reversal of 221171956 is 659171122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221171957) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1201930 + ... + 1202113.

It is an arithmetic number, because the mean of its divisors is an integer number (33656616).

Almost surely, 2^221171956 is an apocalyptic number.

It is an amenable number.

221171956 is a deficient number, since it is larger than the sum of its proper divisors (182707436).

221171956 is a wasteful number, since it uses less digits than its factorization.

221171956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2404070 (or 2404068 counting only the distinct ones).

The product of its digits is 7560, while the sum is 34.

The square root of 221171956 is about 14871.8511288945. The cubic root of 221171956 is about 604.7511268340.

The spelling of 221171956 in words is "two hundred twenty-one million, one hundred seventy-one thousand, nine hundred fifty-six".