1187347221 has 64 divisors (see below), whose sum is σ = 1896652800. Its totient is φ = 731939328.

The previous prime is 1187347199. The next prime is 1187347223. The reversal of 1187347221 is 1227437811.

1187347221 is a `hidden beast` number, since 1 + 187 + 3 + 472 + 2 + 1 = 666.

It is not a de Polignac number, because 1187347221 - 2¹⁰ = 1187346197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1187347223) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5324316 + ... + 5324538.

It is an arithmetic number, because the mean of its divisors is an integer number (29635200).

Almost surely, 2^1187347221 is an apocalyptic number.

It is an amenable number.

1187347221 is a deficient number, since it is larger than the sum of its proper divisors (709305579).

1187347221 is a wasteful number, since it uses less digits than its factorization.

1187347221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455 (or 449 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 1187347221 is about 34457.9050582011. The cubic root of 1187347221 is about 1058.9104804394.

The spelling of 1187347221 in words is "one billion, one hundred eighty-seven million, three hundred forty-seven thousand, two hundred twenty-one".