138966287 has 2 divisors, whose sum is σ = 138966288. Its totient is φ = 138966286.

The previous prime is 138966283. The next prime is 138966329. The reversal of 138966287 is 782669831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138966287 - 2² = 138966283 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138966281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69483143 + 69483144.

It is an arithmetic number, because the mean of its divisors is an integer number (69483144).

Almost surely, 2^138966287 is an apocalyptic number.

138966287 is a deficient number, since it is larger than the sum of its proper divisors (1).

138966287 is an equidigital number, since it uses as much as digits as its factorization.

138966287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 50.

The square root of 138966287 is about 11788.3962861790. The cubic root of 138966287 is about 517.9682640326.

It can be divided in two parts, 1389 and 66287, that added together give a palindrome (67676).

The spelling of 138966287 in words is "one hundred thirty-eight million, nine hundred sixty-six thousand, two hundred eighty-seven".