1147170721 has 4 divisors (see below), whose sum is σ = 1147461444. Its totient is φ = 1146880000.

The previous prime is 1147170667. The next prime is 1147170737. The reversal of 1147170721 is 1270717411.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1270717411 = 17 ⋅74748083.

It can be written as a sum of positive squares in 2 ways, for example, as 347412321 + 799758400 = 18639^2 + 28280^2 .

It is a cyclic number.

It is not a de Polignac number, because 1147170721 - 2¹³ = 1147162529 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1147170121) 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, 139360 + ... + 147361.

It is an arithmetic number, because the mean of its divisors is an integer number (286865361).

Almost surely, 2^1147170721 is an apocalyptic number.

It is an amenable number.

1147170721 is a deficient number, since it is larger than the sum of its proper divisors (290723).

1147170721 is an equidigital number, since it uses as much as digits as its factorization.

1147170721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290722.

The product of its (nonzero) digits is 2744, while the sum is 31.

The square root of 1147170721 is about 33869.9087834615. The cubic root of 1147170721 is about 1046.8296574418.

The spelling of 1147170721 in words is "one billion, one hundred forty-seven million, one hundred seventy thousand, seven hundred twenty-one".