7287991331 has 2 divisors, whose sum is σ = 7287991332. Its totient is φ = 7287991330.

The previous prime is 7287991297. The next prime is 7287991411. The reversal of 7287991331 is 1331997827.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 7287991331 - 2²⁶ = 7220882467 is a prime.

It is a super-2 number, since 2×7287991331² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 7287991331.

It is not a weakly prime, because it can be changed into another prime (7287991231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3643995665 + 3643995666.

It is an arithmetic number, because the mean of its divisors is an integer number (3643995666).

Almost surely, 2^7287991331 is an apocalyptic number.

7287991331 is a deficient number, since it is larger than the sum of its proper divisors (1).

7287991331 is an equidigital number, since it uses as much as digits as its factorization.

7287991331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 571536, while the sum is 50.

The square root of 7287991331 is about 85369.7331084032. The cubic root of 7287991331 is about 1938.8131163496.

The spelling of 7287991331 in words is "seven billion, two hundred eighty-seven million, nine hundred ninety-one thousand, three hundred thirty-one".