726561 has 24 divisors (see below), whose sum is σ = 1179360. Its totient is φ = 427200.

The previous prime is 726559. The next prime is 726589. The reversal of 726561 is 165627.

726561 = T₉₀ + T₉₁ + ... + T₁₇₁.

726561 is a `hidden beast` number, since 7 + 2 + 656 + 1 = 666.

It is not a de Polignac number, because 726561 - 2¹ = 726559 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

726561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (726521) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3970 + ... + 4148.

It is an arithmetic number, because the mean of its divisors is an integer number (49140).

2⁷²⁶⁵⁶¹ is an apocalyptic number.

It is an amenable number.

726561 is a deficient number, since it is larger than the sum of its proper divisors (452799).

726561 is a wasteful number, since it uses less digits than its factorization.

726561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237 (or 234 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 726561 is about 852.3854761785. The cubic root of 726561 is about 89.8995174854.

The spelling of 726561 in words is "seven hundred twenty-six thousand, five hundred sixty-one".