721311212 has 18 divisors (see below), whose sum is σ = 1332230508. Its totient is φ = 341673048.

The previous prime is 721311191. The next prime is 721311233. The reversal of 721311212 is 212113127.

It is an interprime number because it is at equal distance from previous prime (721311191) and next prime (721311233).

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 248318 + ... + 251205.

It is an arithmetic number, because the mean of its divisors is an integer number (74012806).

Almost surely, 2^721311212 is an apocalyptic number.

It is an amenable number.

721311212 is a deficient number, since it is larger than the sum of its proper divisors (610919296).

721311212 is a wasteful number, since it uses less digits than its factorization.

721311212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499565 (or 499544 counting only the distinct ones).

The product of its digits is 168, while the sum is 20.

The square root of 721311212 is about 26857.2376092553. The cubic root of 721311212 is about 896.8247000762.

Adding to 721311212 its reverse (212113127), we get a palindrome (933424339).

The spelling of 721311212 in words is "seven hundred twenty-one million, three hundred eleven thousand, two hundred twelve".