221309236 has 12 divisors (see below), whose sum is σ = 393855840. Its totient is φ = 108779000.

The previous prime is 221309233. The next prime is 221309287. The reversal of 221309236 is 632903122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221309233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 468640 + ... + 469111.

It is an arithmetic number, because the mean of its divisors is an integer number (32821320).

Almost surely, 2^221309236 is an apocalyptic number.

It is an amenable number.

221309236 is a deficient number, since it is larger than the sum of its proper divisors (172546604).

221309236 is a wasteful number, since it uses less digits than its factorization.

221309236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 937814 (or 937812 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 221309236 is about 14876.4658437412. The cubic root of 221309236 is about 604.8762226575.

The spelling of 221309236 in words is "two hundred twenty-one million, three hundred nine thousand, two hundred thirty-six".