721617064 has 16 divisors (see below), whose sum is σ = 1546322400. Its totient is φ = 309264432.

The previous prime is 721617041. The next prime is 721617067. The reversal of 721617064 is 460716127.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (721617067) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6442954 + ... + 6443065.

It is an arithmetic number, because the mean of its divisors is an integer number (96645150).

Almost surely, 2^721617064 is an apocalyptic number.

It is an amenable number.

721617064 is an abundant number, since it is smaller than the sum of its proper divisors (824705336).

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

721617064 is a wasteful number, since it uses less digits than its factorization.

721617064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12886032 (or 12886028 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 721617064 is about 26862.9310388870. The cubic root of 721617064 is about 896.9514400388.

The spelling of 721617064 in words is "seven hundred twenty-one million, six hundred seventeen thousand, sixty-four".