220661620721 has 8 divisors (see below), whose sum is σ = 223790356224. Its totient is φ = 217533463840.

The previous prime is 220661620703. The next prime is 220661620723. The reversal of 220661620721 is 127026166022.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 220661620721 - 2¹⁰ = 220661619697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220661620723) 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, 654536 + ... + 932598.

It is an arithmetic number, because the mean of its divisors is an integer number (27973794528).

Almost surely, 2^220661620721 is an apocalyptic number.

It is an amenable number.

220661620721 is a deficient number, since it is larger than the sum of its proper divisors (3128735503).

220661620721 is a wasteful number, since it uses less digits than its factorization.

220661620721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289311.

The product of its (nonzero) digits is 24192, while the sum is 35.

Adding to 220661620721 its reverse (127026166022), we get a palindrome (347687786743).

The spelling of 220661620721 in words is "two hundred twenty billion, six hundred sixty-one million, six hundred twenty thousand, seven hundred twenty-one".