661695 has 16 divisors (see below), whose sum is σ = 1093632. Its totient is φ = 341280.

The previous prime is 661679. The next prime is 661697. The reversal of 661695 is 596166.

661695 = T₁₁₄ + T₁₁₅ + ... + T₁₇₅.

It is not a de Polignac number, because 661695 - 2⁴ = 661679 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661697) 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 15 ways as a sum of consecutive naturals, for example, 247 + ... + 1176.

It is an arithmetic number, because the mean of its divisors is an integer number (68352).

2⁶⁶¹⁶⁹⁵ is an apocalyptic number.

661695 is a deficient number, since it is larger than the sum of its proper divisors (431937).

661695 is a wasteful number, since it uses less digits than its factorization.

661695 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1462.

The product of its digits is 9720, while the sum is 33.

The square root of 661695 is about 813.4463719263. The cubic root of 661695 is about 87.1403468646.

The spelling of 661695 in words is "six hundred sixty-one thousand, six hundred ninety-five".