221231236 has 6 divisors (see below), whose sum is σ = 387154670. Its totient is φ = 110615616.

The previous prime is 221231233. The next prime is 221231239. The reversal of 221231236 is 632132122.

221231236 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221231233) and next prime (221231239).

It can be written as a sum of positive squares in only one way, i.e., 142802500 + 78428736 = 11950^2 + 8856^2 .

It is a super-3 number, since 3×221231236³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (221231233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27653901 + ... + 27653908.

Almost surely, 2^221231236 is an apocalyptic number.

It is an amenable number.

221231236 is a deficient number, since it is larger than the sum of its proper divisors (165923434).

221231236 is a wasteful number, since it uses less digits than its factorization.

221231236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55307813 (or 55307811 counting only the distinct ones).

The product of its digits is 864, while the sum is 22.

The square root of 221231236 is about 14873.8440223098. The cubic root of 221231236 is about 604.8051518334.

Adding to 221231236 its reverse (632132122), we get a palindrome (853363358).

The spelling of 221231236 in words is "two hundred twenty-one million, two hundred thirty-one thousand, two hundred thirty-six".