220649581 has 8 divisors (see below), whose sum is σ = 224008064. Its totient is φ = 217300320.

The previous prime is 220649567. The next prime is 220649591. The reversal of 220649581 is 185946022.

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

It is a 5-Lehmer number, since φ(220649581) divides (220649581-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 220649581 - 2¹⁵ = 220616813 is a prime.

It is a super-2 number, since 2×220649581² = 97372475190951122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 220649581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220649521) 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, 57340 + ... + 61066.

It is an arithmetic number, because the mean of its divisors is an integer number (28001008).

Almost surely, 2^220649581 is an apocalyptic number.

It is an amenable number.

220649581 is a deficient number, since it is larger than the sum of its proper divisors (3358483).

220649581 is an equidigital number, since it uses as much as digits as its factorization.

220649581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4611.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 220649581 is about 14854.2782052848. The cubic root of 220649581 is about 604.2746410102.

The spelling of 220649581 in words is "two hundred twenty million, six hundred forty-nine thousand, five hundred eighty-one".