721687266 has 32 divisors (see below), whose sum is σ = 1607155200. Its totient is φ = 240051600.

The previous prime is 721687259. The next prime is 721687297. The reversal of 721687266 is 662786127.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11916 + ... + 39816.

It is an arithmetic number, because the mean of its divisors is an integer number (50223600).

Almost surely, 2^721687266 is an apocalyptic number.

721687266 is an abundant number, since it is smaller than the sum of its proper divisors (885467934).

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

721687266 is a wasteful number, since it uses less digits than its factorization.

721687266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28391 (or 28385 counting only the distinct ones).

The product of its digits is 338688, while the sum is 45.

The square root of 721687266 is about 26864.2376776264. The cubic root of 721687266 is about 896.9805255221.

The spelling of 721687266 in words is "seven hundred twenty-one million, six hundred eighty-seven thousand, two hundred sixty-six".