221439986 has 4 divisors (see below), whose sum is σ = 332159982. Its totient is φ = 110719992.

The previous prime is 221439979. The next prime is 221439997. The reversal of 221439986 is 689934122.

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., 216237025 + 5202961 = 14705^2 + 2281^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55359995 + ... + 55359998.

Almost surely, 2^221439986 is an apocalyptic number.

221439986 is a deficient number, since it is larger than the sum of its proper divisors (110719996).

221439986 is a wasteful number, since it uses less digits than its factorization.

221439986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110719995.

The product of its digits is 186624, while the sum is 44.

The square root of 221439986 is about 14880.8597197877. The cubic root of 221439986 is about 604.9953199556.

The spelling of 221439986 in words is "two hundred twenty-one million, four hundred thirty-nine thousand, nine hundred eighty-six".