221788036 has 6 divisors (see below), whose sum is σ = 388129070. Its totient is φ = 110894016.

The previous prime is 221788033. The next prime is 221788037. The reversal of 221788036 is 630887122.

It can be written as a sum of positive squares in only one way, i.e., 194435136 + 27352900 = 13944^2 + 5230^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221787986 and 221788004.

It is not an unprimeable number, because it can be changed into a prime (221788031) 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 as a sum of consecutive naturals, namely, 27723501 + ... + 27723508.

Almost surely, 2^221788036 is an apocalyptic number.

It is an amenable number.

221788036 is a deficient number, since it is larger than the sum of its proper divisors (166341034).

221788036 is a wasteful number, since it uses less digits than its factorization.

221788036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55447013 (or 55447011 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 221788036 is about 14892.5496809646. The cubic root of 221788036 is about 605.3121227159.

The spelling of 221788036 in words is "two hundred twenty-one million, seven hundred eighty-eight thousand, thirty-six".