721317228 has 48 divisors (see below), whose sum is σ = 1696391424. Its totient is φ = 238546240.

The previous prime is 721317209. The next prime is 721317229. The reversal of 721317228 is 822713127.

It is not an unprimeable number, because it can be changed into a prime (721317229) 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, 1294726 + ... + 1295282.

It is an arithmetic number, because the mean of its divisors is an integer number (35341488).

Almost surely, 2^721317228 is an apocalyptic number.

It is an amenable number.

721317228 is an abundant number, since it is smaller than the sum of its proper divisors (975074196).

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

721317228 is a wasteful number, since it uses less digits than its factorization.

721317228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222 (or 1220 counting only the distinct ones).

The product of its digits is 9408, while the sum is 33.

The square root of 721317228 is about 26857.3496086267. The cubic root of 721317228 is about 896.8271933515.

The spelling of 721317228 in words is "seven hundred twenty-one million, three hundred seventeen thousand, two hundred twenty-eight".