660428 has 12 divisors (see below), whose sum is σ = 1184232. Its totient is φ = 322080.

The previous prime is 660409. The next prime is 660449. The reversal of 660428 is 824066.

It is a junction number, because it is equal to n+sod(n) for n = 660397 and 660406.

It is an unprimeable number.

660428 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, 1850 + ... + 2177.

It is an arithmetic number, because the mean of its divisors is an integer number (98686).

2⁶⁶⁰⁴²⁸ is an apocalyptic number.

It is an amenable number.

660428 is a deficient number, since it is larger than the sum of its proper divisors (523804).

660428 is a wasteful number, since it uses less digits than its factorization.

660428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4072 (or 4070 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 660428 is about 812.6672135628. The cubic root of 660428 is about 87.0846931456.

The spelling of 660428 in words is "six hundred sixty thousand, four hundred twenty-eight".