1187121121 has 4 divisors (see below), whose sum is σ = 1249601200. Its totient is φ = 1124641044.

The previous prime is 1187121113. The next prime is 1187121127. The reversal of 1187121121 is 1211217811.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1187121121 - 2³ = 1187121113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1187121127) 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 3 ways as a sum of consecutive naturals, for example, 31240011 + ... + 31240048.

It is an arithmetic number, because the mean of its divisors is an integer number (312400300).

Almost surely, 2^1187121121 is an apocalyptic number.

It is an amenable number.

1187121121 is a deficient number, since it is larger than the sum of its proper divisors (62480079).

1187121121 is an equidigital number, since it uses as much as digits as its factorization.

1187121121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62480078.

The product of its digits is 224, while the sum is 25.

The square root of 1187121121 is about 34454.6240873413. The cubic root of 1187121121 is about 1058.8432620066.

Adding to 1187121121 its reverse (1211217811), we get a palindrome (2398338932).

The spelling of 1187121121 in words is "one billion, one hundred eighty-seven million, one hundred twenty-one thousand, one hundred twenty-one".