721722646 has 4 divisors (see below), whose sum is σ = 1082583972. Its totient is φ = 360861322.

The previous prime is 721722637. The next prime is 721722667. The reversal of 721722646 is 646227127.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 180430660 + ... + 180430663.

It is an arithmetic number, because the mean of its divisors is an integer number (270645993).

Almost surely, 2^721722646 is an apocalyptic number.

721722646 is a deficient number, since it is larger than the sum of its proper divisors (360861326).

721722646 is a wasteful number, since it uses less digits than its factorization.

721722646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360861325.

The product of its digits is 56448, while the sum is 37.

The square root of 721722646 is about 26864.8961658146. The cubic root of 721722646 is about 896.9951831418.

The spelling of 721722646 in words is "seven hundred twenty-one million, seven hundred twenty-two thousand, six hundred forty-six".