661207 has 4 divisors (see below), whose sum is σ = 677376. Its totient is φ = 645040.

The previous prime is 661201. The next prime is 661217. The reversal of 661207 is 702166.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 661207 - 2¹¹ = 659159 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661201) 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 3 ways as a sum of consecutive naturals, for example, 8023 + ... + 8104.

It is an arithmetic number, because the mean of its divisors is an integer number (169344).

2⁶⁶¹²⁰⁷ is an apocalyptic number.

661207 is a deficient number, since it is larger than the sum of its proper divisors (16169).

661207 is a wasteful number, since it uses less digits than its factorization.

661207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16168.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 661207 is about 813.1463582898. The cubic root of 661207 is about 87.1189195970.

It can be divided in two parts, 661 and 207, that added together give a palindrome (868).

The spelling of 661207 in words is "six hundred sixty-one thousand, two hundred seven".