220312661 has 4 divisors (see below), whose sum is σ = 220420512. Its totient is φ = 220204812.

The previous prime is 220312621. The next prime is 220312709. The reversal of 220312661 is 166213022.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-220312661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220312621) 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 in 3 ways as a sum of consecutive naturals, for example, 50801 + ... + 54966.

It is an arithmetic number, because the mean of its divisors is an integer number (55105128).

Almost surely, 2^220312661 is an apocalyptic number.

It is an amenable number.

220312661 is a deficient number, since it is larger than the sum of its proper divisors (107851).

220312661 is a wasteful number, since it uses less digits than its factorization.

220312661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107850.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 220312661 is about 14842.9330322548. The cubic root of 220312661 is about 603.9669194125.

Adding to 220312661 its reverse (166213022), we get a palindrome (386525683).

The spelling of 220312661 in words is "two hundred twenty million, three hundred twelve thousand, six hundred sixty-one".