1131209172 has 96 divisors (see below), whose sum is σ = 3113510400. Its totient is φ = 353949696.

The previous prime is 1131209153. The next prime is 1131209197. The reversal of 1131209172 is 2719021311.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1088229 + ... + 1089267.

It is an arithmetic number, because the mean of its divisors is an integer number (32432400).

Almost surely, 2^1131209172 is an apocalyptic number.

1131209172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1131209172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1556755200).

1131209172 is an abundant number, since it is smaller than the sum of its proper divisors (1982301228).

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

1131209172 is a wasteful number, since it uses less digits than its factorization.

1131209172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1662 (or 1654 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 27.

The square root of 1131209172 is about 33633.4531679398. The cubic root of 1131209172 is about 1041.9518240136.

The spelling of 1131209172 in words is "one billion, one hundred thirty-one million, two hundred nine thousand, one hundred seventy-two".