721320771 has 16 divisors (see below), whose sum is σ = 970768800. Its totient is φ = 476394240.

The previous prime is 721320739. The next prime is 721320839. The reversal of 721320771 is 177023127.

It is not a de Polignac number, because 721320771 - 2⁵ = 721320739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (721320071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 186271 + ... + 190103.

It is an arithmetic number, because the mean of its divisors is an integer number (60673050).

Almost surely, 2^721320771 is an apocalyptic number.

721320771 is a deficient number, since it is larger than the sum of its proper divisors (249448029).

721320771 is a wasteful number, since it uses less digits than its factorization.

721320771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4406.

The product of its (nonzero) digits is 4116, while the sum is 30.

The square root of 721320771 is about 26857.4155681443. The cubic root of 721320771 is about 896.8286617085.

Adding to 721320771 its reverse (177023127), we get a palindrome (898343898).

The spelling of 721320771 in words is "seven hundred twenty-one million, three hundred twenty thousand, seven hundred seventy-one".