221512 has 8 divisors (see below), whose sum is σ = 415350. Its totient is φ = 110752.

The previous prime is 221509. The next prime is 221537. The reversal of 221512 is 215122.

221512 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 217156 + 4356 = 466^2 + 66^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×221512² = 98135132288, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221492 and 221501.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13837 + ... + 13852.

2²²¹⁵¹² is an apocalyptic number.

It is an amenable number.

221512 is a deficient number, since it is larger than the sum of its proper divisors (193838).

221512 is a wasteful number, since it uses less digits than its factorization.

221512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27695 (or 27691 counting only the distinct ones).

The product of its digits is 40, while the sum is 13.

The square root of 221512 is about 470.6506135128. The cubic root of 221512 is about 60.5060895903.

Adding to 221512 its reverse (215122), we get a palindrome (436634).

The spelling of 221512 in words is "two hundred twenty-one thousand, five hundred twelve".