220700721 has 8 divisors (see below), whose sum is σ = 295894144. Its totient is φ = 146320560.

The previous prime is 220700717. The next prime is 220700723. The reversal of 220700721 is 127007022.

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

It is not a de Polignac number, because 220700721 - 2² = 220700717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220700723) 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, 202681 + ... + 203766.

It is an arithmetic number, because the mean of its divisors is an integer number (36986768).

Almost surely, 2^220700721 is an apocalyptic number.

It is an amenable number.

220700721 is a deficient number, since it is larger than the sum of its proper divisors (75193423).

220700721 is a wasteful number, since it uses less digits than its factorization.

220700721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406631.

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 220700721 is about 14855.9994951535. Note that the first 3 decimals coincide. The cubic root of 220700721 is about 604.3213216910.

Adding to 220700721 its reverse (127007022), we get a palindrome (347707743).

The spelling of 220700721 in words is "two hundred twenty million, seven hundred thousand, seven hundred twenty-one".