661924 has 12 divisors (see below), whose sum is σ = 1168384. Its totient is φ = 328104.

The previous prime is 661909. The next prime is 661931. The reversal of 661924 is 429166.

It is a junction number, because it is equal to n+sod(n) for n = 661892 and 661901.

It is an unprimeable number.

661924 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144 + ... + 1159.

2⁶⁶¹⁹²⁴ is an apocalyptic number.

It is an amenable number.

661924 is a deficient number, since it is larger than the sum of its proper divisors (506460).

661924 is a wasteful number, since it uses less digits than its factorization.

661924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434 (or 1432 counting only the distinct ones).

The product of its digits is 2592, while the sum is 28.

The square root of 661924 is about 813.5871188754. The cubic root of 661924 is about 87.1503982417.

The spelling of 661924 in words is "six hundred sixty-one thousand, nine hundred twenty-four".