661708 has 24 divisors (see below), whose sum is σ = 1264032. Its totient is φ = 301824.

The previous prime is 661697. The next prime is 661721. The reversal of 661708 is 807166.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2385 + ... + 2647.

It is an arithmetic number, because the mean of its divisors is an integer number (52668).

2⁶⁶¹⁷⁰⁸ is an apocalyptic number.

661708 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

661708 is a deficient number, since it is larger than the sum of its proper divisors (602324).

661708 is a wasteful number, since it uses less digits than its factorization.

661708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321 (or 319 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 661708 is about 813.4543625797. The cubic root of 661708 is about 87.1409175289.

It can be divided in two parts, 661 and 708, that added together give a square (1369 = 37²).

The spelling of 661708 in words is "six hundred sixty-one thousand, seven hundred eight".