220317921 has 8 divisors (see below), whose sum is σ = 326396960. Its totient is φ = 146878596.

The previous prime is 220317917. The next prime is 220317953. The reversal of 220317921 is 129713022.

It is not a de Polignac number, because 220317921 - 2² = 220317917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 8159923 = 220317921 / (2 + 2 + 0 + 3 + 1 + 7 + 9 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (220317121) 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, 4079935 + ... + 4079988.

It is an arithmetic number, because the mean of its divisors is an integer number (40799620).

Almost surely, 2^220317921 is an apocalyptic number.

It is an amenable number.

220317921 is a deficient number, since it is larger than the sum of its proper divisors (106079039).

220317921 is an equidigital number, since it uses as much as digits as its factorization.

220317921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8159932 (or 8159926 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 220317921 is about 14843.1102198966. The cubic root of 220317921 is about 603.9717259764.

The spelling of 220317921 in words is "two hundred twenty million, three hundred seventeen thousand, nine hundred twenty-one".