661726 has 16 divisors (see below), whose sum is σ = 1104768. Its totient is φ = 295200.

The previous prime is 661721. The next prime is 661741. The reversal of 661726 is 627166.

661726 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 661694 and 661703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 396 + ... + 1216.

It is an arithmetic number, because the mean of its divisors is an integer number (69048).

2⁶⁶¹⁷²⁶ is an apocalyptic number.

661726 is a deficient number, since it is larger than the sum of its proper divisors (443042).

661726 is a wasteful number, since it uses less digits than its factorization.

661726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 867.

The product of its digits is 3024, while the sum is 28.

The square root of 661726 is about 813.4654264319. The cubic root of 661726 is about 87.1417076671.

The spelling of 661726 in words is "six hundred sixty-one thousand, seven hundred twenty-six".