722656 has 24 divisors (see below), whose sum is σ = 1552824. Its totient is φ = 328320.

The previous prime is 722639. The next prime is 722663. The reversal of 722656 is 656227.

It is a d-powerful number, because it can be written as 7⁶ + 2 + 6⁴ + 2¹⁹ + 5⁷ + 6⁴ .

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, 675 + ... + 1378.

It is an arithmetic number, because the mean of its divisors is an integer number (64701).

2⁷²²⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

722656 is an abundant number, since it is smaller than the sum of its proper divisors (830168).

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

722656 is a wasteful number, since it uses less digits than its factorization.

722656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2074 (or 2066 counting only the distinct ones).

The product of its digits is 5040, while the sum is 28.

The square root of 722656 is about 850.0917597530. The cubic root of 722656 is about 89.7381690527.

It can be divided in two parts, 722 and 656, that added together give a triangular number (1378 = T₅₂).

The spelling of 722656 in words is "seven hundred twenty-two thousand, six hundred fifty-six".