139987 has 2 divisors, whose sum is σ = 139988. Its totient is φ = 139986.

The previous prime is 139981. The next prime is 139991. The reversal of 139987 is 789931.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139987 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69993 + 69994.

It is an arithmetic number, because the mean of its divisors is an integer number (69994).

2¹³⁹⁹⁸⁷ is an apocalyptic number.

139987 is a deficient number, since it is larger than the sum of its proper divisors (1).

139987 is an equidigital number, since it uses as much as digits as its factorization.

139987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13608, while the sum is 37.

The square root of 139987 is about 374.1483662934. The cubic root of 139987 is about 51.9233337682.

It can be divided in two parts, 13 and 9987, that added together give a 4-th power (10000 = 10⁴).

The spelling of 139987 in words is "one hundred thirty-nine thousand, nine hundred eighty-seven".