1209156 has 48 divisors (see below), whose sum is σ = 3179904. Its totient is φ = 354816.

The previous prime is 1209151. The next prime is 1209163. The reversal of 1209156 is 6519021.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1209151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3420 + ... + 3756.

It is an arithmetic number, because the mean of its divisors is an integer number (66248).

2^1209156 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1209156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1589952).

1209156 is an abundant number, since it is smaller than the sum of its proper divisors (1970748).

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

1209156 is a wasteful number, since it uses less digits than its factorization.

1209156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 1209156 is about 1099.6162967144. The cubic root of 1209156 is about 106.5354419279.

The spelling of 1209156 in words is "one million, two hundred nine thousand, one hundred fifty-six".