721312722 has 64 divisors (see below), whose sum is σ = 1758879360. Its totient is φ = 217743552.

The previous prime is 721312721. The next prime is 721312723. The reversal of 721312722 is 227213127.

It is an interprime number because it is at equal distance from previous prime (721312721) and next prime (721312723).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (721312721) 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 31 ways as a sum of consecutive naturals, for example, 27513 + ... + 46899.

It is an arithmetic number, because the mean of its divisors is an integer number (27482490).

Almost surely, 2^721312722 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721312722, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (879439680).

721312722 is an abundant number, since it is smaller than the sum of its proper divisors (1037566638).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721312722 is a wasteful number, since it uses less digits than its factorization.

721312722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19464 (or 19458 counting only the distinct ones).

The product of its digits is 2352, while the sum is 27.

The square root of 721312722 is about 26857.2657208436. The cubic root of 721312722 is about 896.8253258830.

Adding to 721312722 its reverse (227213127), we get a palindrome (948525849).

The spelling of 721312722 in words is "seven hundred twenty-one million, three hundred twelve thousand, seven hundred twenty-two".