661136 has 20 divisors (see below), whose sum is σ = 1464192. Its totient is φ = 283296.

The previous prime is 661121. The next prime is 661139. The reversal of 661136 is 631166.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (661139) by changing a digit.

661136 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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, 2840 + ... + 3063.

2⁶⁶¹¹³⁶ is an apocalyptic number.

It is an amenable number.

661136 is an abundant number, since it is smaller than the sum of its proper divisors (803056).

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

661136 is a wasteful number, since it uses less digits than its factorization.

661136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5918 (or 5912 counting only the distinct ones).

The product of its digits is 648, while the sum is 23.

The square root of 661136 is about 813.1026995405. The cubic root of 661136 is about 87.1158012268.

It can be divided in two parts, 661 and 136, that added together give a palindrome (797).

The spelling of 661136 in words is "six hundred sixty-one thousand, one hundred thirty-six".