1231161120 has 480 divisors, whose sum is σ = 5102165376. Its totient is φ = 273715200.

The previous prime is 1231161091. The next prime is 1231161167. The reversal of 1231161120 is 211611321.

1231161120 is a `hidden beast` number, since 1 + 2 + 31 + 1 + 611 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

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

It is a junction number, because it is equal to n+sod(n) for n = 1231161093 and 1231161102.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3719355 + ... + 3719685.

Almost surely, 2^1231161120 is an apocalyptic number.

1231161120 is a gapful number since it is divisible by the number (10) 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 1231161120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2551082688).

1231161120 is an abundant number, since it is smaller than the sum of its proper divisors (3871004256).

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

1231161120 is a wasteful number, since it uses less digits than its factorization.

1231161120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 389 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 1231161120 is about 35087.9056086282. The cubic root of 1231161120 is about 1071.7783105104.

Adding to 1231161120 its reverse (211611321), we get a palindrome (1442772441).

The spelling of 1231161120 in words is "one billion, two hundred thirty-one million, one hundred sixty-one thousand, one hundred twenty".