721944428 has 12 divisors (see below), whose sum is σ = 1264040232. Its totient is φ = 360790080.

The previous prime is 721944427. The next prime is 721944449. The reversal of 721944428 is 824449127.

It is not an unprimeable number, because it can be changed into a prime (721944427) 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 3 ways as a sum of consecutive naturals, for example, 36413 + ... + 52628.

It is an arithmetic number, because the mean of its divisors is an integer number (105336686).

Almost surely, 2^721944428 is an apocalyptic number.

It is an amenable number.

721944428 is a deficient number, since it is larger than the sum of its proper divisors (542095804).

721944428 is a wasteful number, since it uses less digits than its factorization.

721944428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91072 (or 91070 counting only the distinct ones).

The product of its digits is 129024, while the sum is 41.

The square root of 721944428 is about 26869.0235773465. The cubic root of 721944428 is about 897.0870545427.

The spelling of 721944428 in words is "seven hundred twenty-one million, nine hundred forty-four thousand, four hundred twenty-eight".