721768 has 16 divisors (see below), whose sum is σ = 1370880. Its totient is φ = 356208.

The previous prime is 721739. The next prime is 721783. The reversal of 721768 is 867127.

It is a happy number.

Its product of digits (4704) is a multiple of the sum of its prime factors (1176).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121 + ... + 1207.

It is an arithmetic number, because the mean of its divisors is an integer number (85680).

2⁷²¹⁷⁶⁸ is an apocalyptic number.

It is an amenable number.

721768 is a deficient number, since it is larger than the sum of its proper divisors (649112).

721768 is a wasteful number, since it uses less digits than its factorization.

721768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1176 (or 1172 counting only the distinct ones).

The product of its digits is 4704, while the sum is 31.

The square root of 721768 is about 849.5693026469. The cubic root of 721768 is about 89.7013972200.

The spelling of 721768 in words is "seven hundred twenty-one thousand, seven hundred sixty-eight".