7987139 has 2 divisors, whose sum is σ = 7987140. Its totient is φ = 7987138.

The previous prime is 7987129. The next prime is 7987223. The reversal of 7987139 is 9317897.

It is a weak prime.

It is an emirp because it is prime and its reverse (9317897) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7987139 - 2⁴ = 7987123 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7987139.

It is not a weakly prime, because it can be changed into another prime (7987129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3993569 + 3993570.

It is an arithmetic number, because the mean of its divisors is an integer number (3993570).

Almost surely, 2^7987139 is an apocalyptic number.

7987139 is a deficient number, since it is larger than the sum of its proper divisors (1).

7987139 is an equidigital number, since it uses as much as digits as its factorization.

7987139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 95256, while the sum is 44.

The square root of 7987139 is about 2826.1526851888. The cubic root of 7987139 is about 199.8927675162.

The spelling of 7987139 in words is "seven million, nine hundred eighty-seven thousand, one hundred thirty-nine".