221986 has 8 divisors (see below), whose sum is σ = 352620. Its totient is φ = 104448.

The previous prime is 221957. The next prime is 221987. The reversal of 221986 is 689122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 219961 + 2025 = 469^2 + 45^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (221987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3231 + ... + 3298.

2²²¹⁹⁸⁶ is an apocalyptic number.

221986 is a deficient number, since it is larger than the sum of its proper divisors (130634).

221986 is a wasteful number, since it uses less digits than its factorization.

221986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6548.

The product of its digits is 1728, while the sum is 28.

The square root of 221986 is about 471.1539026688. The cubic root of 221986 is about 60.5492166052.

The spelling of 221986 in words is "two hundred twenty-one thousand, nine hundred eighty-six".