661236 has 12 divisors (see below), whose sum is σ = 1542912. Its totient is φ = 220408.

The previous prime is 661231. The next prime is 661237. The reversal of 661236 is 632166.

661236 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27540 + ... + 27563.

It is an arithmetic number, because the mean of its divisors is an integer number (128576).

2⁶⁶¹²³⁶ is an apocalyptic number.

It is an amenable number.

661236 is an abundant number, since it is smaller than the sum of its proper divisors (881676).

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

661236 is a wasteful number, since it uses less digits than its factorization.

661236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55110 (or 55108 counting only the distinct ones).

The product of its digits is 1296, while the sum is 24.

The square root of 661236 is about 813.1641900625. The cubic root of 661236 is about 87.1201932334.

The spelling of 661236 in words is "six hundred sixty-one thousand, two hundred thirty-six".