220639 has 8 divisors (see below), whose sum is σ = 235872. Its totient is φ = 205920.

The previous prime is 220613. The next prime is 220663. The reversal of 220639 is 936022.

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

It is a cyclic number.

It is not a de Polignac number, because 220639 - 2⁷ = 220511 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220699) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1129 + ... + 1309.

It is an arithmetic number, because the mean of its divisors is an integer number (29484).

2²²⁰⁶³⁹ is an apocalyptic number.

220639 is a deficient number, since it is larger than the sum of its proper divisors (15233).

220639 is a wasteful number, since it uses less digits than its factorization.

220639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 220639 is about 469.7222583613. The cubic root of 220639 is about 60.4264981754.

The spelling of 220639 in words is "two hundred twenty thousand, six hundred thirty-nine".