220086721 has 2 divisors, whose sum is σ = 220086722. Its totient is φ = 220086720.

The previous prime is 220086703. The next prime is 220086733. The reversal of 220086721 is 127680022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 169520400 + 50566321 = 13020^2 + 7111^2 .

It is a cyclic number.

It is not a de Polignac number, because 220086721 - 2⁵ = 220086689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 220086721.

It is not a weakly prime, because it can be changed into another prime (220086791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110043360 + 110043361.

It is an arithmetic number, because the mean of its divisors is an integer number (110043361).

Almost surely, 2^220086721 is an apocalyptic number.

It is an amenable number.

220086721 is a deficient number, since it is larger than the sum of its proper divisors (1).

220086721 is an equidigital number, since it uses as much as digits as its factorization.

220086721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 220086721 is about 14835.3200504741. The cubic root of 220086721 is about 603.7603842087.

The spelling of 220086721 in words is "two hundred twenty million, eighty-six thousand, seven hundred twenty-one".