721644312 has 32 divisors (see below), whose sum is σ = 1805500080. Its totient is φ = 240362880.

The previous prime is 721644311. The next prime is 721644317. The reversal of 721644312 is 213446127.

It is a self number, because there is not a number n which added to its sum of digits gives 721644312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721644311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22258 + ... + 44030.

Almost surely, 2^721644312 is an apocalyptic number.

It is an amenable number.

721644312 is an abundant number, since it is smaller than the sum of its proper divisors (1083855768).

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

721644312 is a wasteful number, since it uses less digits than its factorization.

721644312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23163 (or 23159 counting only the distinct ones).

The product of its digits is 8064, while the sum is 30.

The square root of 721644312 is about 26863.4382013919. The cubic root of 721644312 is about 896.9627294176.

The spelling of 721644312 in words is "seven hundred twenty-one million, six hundred forty-four thousand, three hundred twelve".