1191203121 has 8 divisors (see below), whose sum is σ = 1602842560. Its totient is φ = 786849552.

The previous prime is 1191203113. The next prime is 1191203149. The reversal of 1191203121 is 1213021911.

It is a happy number.

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

It is not a de Polignac number, because 1191203121 - 2³ = 1191203113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1191203161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1821085 + ... + 1821738.

It is an arithmetic number, because the mean of its divisors is an integer number (200355320).

Almost surely, 2^1191203121 is an apocalyptic number.

It is an amenable number.

1191203121 is a deficient number, since it is larger than the sum of its proper divisors (411639439).

1191203121 is a wasteful number, since it uses less digits than its factorization.

1191203121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3642935.

The product of its (nonzero) digits is 108, while the sum is 21.

The square root of 1191203121 is about 34513.8105835910. The cubic root of 1191203121 is about 1060.0555094343.

The spelling of 1191203121 in words is "one billion, one hundred ninety-one million, two hundred three thousand, one hundred twenty-one".