766661 has 8 divisors (see below), whose sum is σ = 904704. Its totient is φ = 635760.

The previous prime is 766651. The next prime is 766679. The reversal of 766661 is 166667.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-766661 is a prime.

It is an Ulam number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (766651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1550 + ... + 1983.

It is an arithmetic number, because the mean of its divisors is an integer number (113088).

2⁷⁶⁶⁶⁶¹ is an apocalyptic number.

It is an amenable number.

766661 is a deficient number, since it is larger than the sum of its proper divisors (138043).

766661 is a wasteful number, since it uses less digits than its factorization.

766661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3571.

The product of its digits is 9072, while the sum is 32.

The square root of 766661 is about 875.5917998702. The cubic root of 766661 is about 91.5238871812.

It can be divided in two parts, 76666 and 1, that added together give a palindrome (76667).

The spelling of 766661 in words is "seven hundred sixty-six thousand, six hundred sixty-one".