220552721 has 2 divisors, whose sum is σ = 220552722. Its totient is φ = 220552720.

The previous prime is 220552691. The next prime is 220552723. The reversal of 220552721 is 127255022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209236225 + 11316496 = 14465^2 + 3364^2 .

It is a cyclic number.

It is not a de Polignac number, because 220552721 - 2¹⁰ = 220551697 is a prime.

Together with 220552723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (220552723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110276360 + 110276361.

It is an arithmetic number, because the mean of its divisors is an integer number (110276361).

Almost surely, 2^220552721 is an apocalyptic number.

It is an amenable number.

220552721 is a deficient number, since it is larger than the sum of its proper divisors (1).

220552721 is an equidigital number, since it uses as much as digits as its factorization.

220552721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 220552721 is about 14851.0175072283. The cubic root of 220552721 is about 604.1862072623.

The spelling of 220552721 in words is "two hundred twenty million, five hundred fifty-two thousand, seven hundred twenty-one".