661508 has 12 divisors (see below), whose sum is σ = 1177680. Its totient is φ = 325032.

The previous prime is 661483. The next prime is 661513. The reversal of 661508 is 805166.

It is an unprimeable number.

661508 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1166 + ... + 1637.

It is an arithmetic number, because the mean of its divisors is an integer number (98140).

2⁶⁶¹⁵⁰⁸ is an apocalyptic number.

It is an amenable number.

661508 is a deficient number, since it is larger than the sum of its proper divisors (516172).

661508 is a wasteful number, since it uses less digits than its factorization.

661508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2866 (or 2864 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 661508 is about 813.3314207628. The cubic root of 661508 is about 87.1321372514.

The spelling of 661508 in words is "six hundred sixty-one thousand, five hundred eight".