661707 has 6 divisors (see below), whose sum is σ = 955812. Its totient is φ = 441132.

The previous prime is 661697. The next prime is 661721. The reversal of 661707 is 707166.

It is not a de Polignac number, because 661707 - 2¹⁰ = 660683 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661777) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36753 + ... + 36770.

It is an arithmetic number, because the mean of its divisors is an integer number (159302).

2⁶⁶¹⁷⁰⁷ is an apocalyptic number.

661707 is a deficient number, since it is larger than the sum of its proper divisors (294105).

661707 is a wasteful number, since it uses less digits than its factorization.

661707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73529 (or 73526 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 661707 is about 813.4537479169. The cubic root of 661707 is about 87.1408736319.

The spelling of 661707 in words is "six hundred sixty-one thousand, seven hundred seven".