661004 has 12 divisors (see below), whose sum is σ = 1163064. Its totient is φ = 328704.

The previous prime is 660983. The next prime is 661009. The reversal of 661004 is 400166.

It is not an unprimeable number, because it can be changed into a prime (661009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 707 + ... + 1349.

It is an arithmetic number, because the mean of its divisors is an integer number (96922).

2⁶⁶¹⁰⁰⁴ is an apocalyptic number.

It is an amenable number.

661004 is a deficient number, since it is larger than the sum of its proper divisors (502060).

661004 is a wasteful number, since it uses less digits than its factorization.

661004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 904 (or 902 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 661004 is about 813.0215249303. The cubic root of 661004 is about 87.1100031000.

The spelling of 661004 in words is "six hundred sixty-one thousand, four".