221638682 has 4 divisors (see below), whose sum is σ = 332458026. Its totient is φ = 110819340.

The previous prime is 221638679. The next prime is 221638717. The reversal of 221638682 is 286836122.

221638682 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 184172041 + 37466641 = 13571^2 + 6121^2 .

It is a super-4 number, since 4×221638682⁴ (a number of 34 digits) contains 4444 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55409669 + ... + 55409672.

Almost surely, 2^221638682 is an apocalyptic number.

221638682 is a deficient number, since it is larger than the sum of its proper divisors (110819344).

221638682 is a wasteful number, since it uses less digits than its factorization.

221638682 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110819343.

The product of its digits is 55296, while the sum is 38.

The square root of 221638682 is about 14887.5344500021. The cubic root of 221638682 is about 605.1762180486.

The spelling of 221638682 in words is "two hundred twenty-one million, six hundred thirty-eight thousand, six hundred eighty-two".