721542646 has 16 divisors (see below), whose sum is σ = 1187955648. Its totient is φ = 325960200.

The previous prime is 721542617. The next prime is 721542677. The reversal of 721542646 is 646245127.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97020 + ... + 104191.

It is an arithmetic number, because the mean of its divisors is an integer number (74247228).

Almost surely, 2^721542646 is an apocalyptic number.

721542646 is a deficient number, since it is larger than the sum of its proper divisors (466413002).

721542646 is a wasteful number, since it uses less digits than its factorization.

721542646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201387.

The product of its digits is 80640, while the sum is 37.

The square root of 721542646 is about 26861.5458602069. The cubic root of 721542646 is about 896.9206057592.

The spelling of 721542646 in words is "seven hundred twenty-one million, five hundred forty-two thousand, six hundred forty-six".