1131981121 has 8 divisors (see below), whose sum is σ = 1149719400. Its totient is φ = 1114354560.

The previous prime is 1131981113. The next prime is 1131981131. The reversal of 1131981121 is 1211891311.

It can be written as a sum of positive squares in 4 ways, for example, as 49900096 + 1082081025 = 7064^2 + 32895^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1131981121 - 2³ = 1131981113 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1131981121.

It is not an unprimeable number, because it can be changed into a prime (1131981101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7390 + ... + 48151.

It is an arithmetic number, because the mean of its divisors is an integer number (143714925).

Almost surely, 2^1131981121 is an apocalyptic number.

It is an amenable number.

1131981121 is a deficient number, since it is larger than the sum of its proper divisors (17738279).

1131981121 is an equidigital number, since it uses as much as digits as its factorization.

1131981121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55859.

The product of its digits is 432, while the sum is 28.

The square root of 1131981121 is about 33644.9271213358. The cubic root of 1131981121 is about 1042.1887830706.

The spelling of 1131981121 in words is "one billion, one hundred thirty-one million, nine hundred eighty-one thousand, one hundred twenty-one".