220611661 has 2 divisors, whose sum is σ = 220611662. Its totient is φ = 220611660.

The previous prime is 220611631. The next prime is 220611667. The reversal of 220611661 is 166116022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162562500 + 58049161 = 12750^2 + 7619^2 .

It is a cyclic number.

It is not a de Polignac number, because 220611661 - 2²⁷ = 86393933 is a prime.

It is equal to p_12154309 and since 220611661 and 12154309 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220611667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110305830 + 110305831.

It is an arithmetic number, because the mean of its divisors is an integer number (110305831).

Almost surely, 2^220611661 is an apocalyptic number.

It is an amenable number.

220611661 is a deficient number, since it is larger than the sum of its proper divisors (1).

220611661 is an equidigital number, since it uses as much as digits as its factorization.

220611661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 220611661 is about 14853.0017504880. The cubic root of 220611661 is about 604.2400229111.

Adding to 220611661 its reverse (166116022), we get a palindrome (386727683).

The spelling of 220611661 in words is "two hundred twenty million, six hundred eleven thousand, six hundred sixty-one".