660761 has 4 divisors (see below), whose sum is σ = 662400. Its totient is φ = 659124.

The previous prime is 660757. The next prime is 660769. The reversal of 660761 is 167066.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 660761 - 2² = 660757 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 660761.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 660761.

It is not an unprimeable number, because it can be changed into a prime (660769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260 + ... + 1178.

It is an arithmetic number, because the mean of its divisors is an integer number (165600).

2⁶⁶⁰⁷⁶¹ is an apocalyptic number.

It is an amenable number.

660761 is a deficient number, since it is larger than the sum of its proper divisors (1639).

660761 is an equidigital number, since it uses as much as digits as its factorization.

660761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1638.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 660761 is about 812.8720686553. The cubic root of 660761 is about 87.0993272568.

The spelling of 660761 in words is "six hundred sixty thousand, seven hundred sixty-one".