1131242420 has 144 divisors (see below), whose sum is σ = 3047466240. Its totient is φ = 348768000.

The previous prime is 1131242401. The next prime is 1131242423. The reversal of 1131242420 is 242421311.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1131242392 and 1131242401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131242423) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1088261 + ... + 1089299.

It is an arithmetic number, because the mean of its divisors is an integer number (21162960).

Almost surely, 2^1131242420 is an apocalyptic number.

1131242420 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 1131242420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1523733120).

1131242420 is an abundant number, since it is smaller than the sum of its proper divisors (1916223820).

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

1131242420 is a wasteful number, since it uses less digits than its factorization.

1131242420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1174 (or 1165 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 1131242420 is about 33633.9474341029. The cubic root of 1131242420 is about 1041.9620321094.

Adding to 1131242420 its reverse (242421311), we get a palindrome (1373663731).

The spelling of 1131242420 in words is "one billion, one hundred thirty-one million, two hundred forty-two thousand, four hundred twenty".