661928 has 16 divisors (see below), whose sum is σ = 1255380. Its totient is φ = 327168.

The previous prime is 661909. The next prime is 661931. The reversal of 661928 is 829166.

It can be written as a sum of positive squares in 2 ways, for example, as 605284 + 56644 = 778^2 + 238^2 .

It is a junction number, because it is equal to n+sod(n) for n = 661894 and 661903.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350 + ... + 1202.

2⁶⁶¹⁹²⁸ is an apocalyptic number.

It is an amenable number.

661928 is a deficient number, since it is larger than the sum of its proper divisors (593452).

661928 is a wasteful number, since it uses less digits than its factorization.

661928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956 (or 952 counting only the distinct ones).

The product of its digits is 5184, while the sum is 32.

The square root of 661928 is about 813.5895771210. The cubic root of 661928 is about 87.1505737910.

The spelling of 661928 in words is "six hundred sixty-one thousand, nine hundred twenty-eight".