661104 has 30 divisors (see below), whose sum is σ = 1850576. Its totient is φ = 220320.

The previous prime is 661103. The next prime is 661109. The reversal of 661104 is 401166.

661104 is a `hidden beast` number, since 661 + 1 + 0 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2152 + ... + 2439.

2⁶⁶¹¹⁰⁴ is an apocalyptic number.

It is an amenable number.

661104 is an abundant number, since it is smaller than the sum of its proper divisors (1189472).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661104 is a wasteful number, since it uses less digits than its factorization.

661104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4605 (or 4596 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 661104 is about 813.0830215913. The cubic root of 661104 is about 87.1143956912.

The spelling of 661104 in words is "six hundred sixty-one thousand, one hundred four".