87138269 has 2 divisors, whose sum is σ = 87138270. Its totient is φ = 87138268.

The previous prime is 87138251. The next prime is 87138299. The reversal of 87138269 is 96283178.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69388900 + 17749369 = 8330^2 + 4213^2 .

It is a cyclic number.

It is not a de Polignac number, because 87138269 - 2⁸ = 87138013 is a prime.

It is a super-2 number, since 2×87138269² = 15186155848632722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87138239) 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, 43569134 + 43569135.

It is an arithmetic number, because the mean of its divisors is an integer number (43569135).

Almost surely, 2^87138269 is an apocalyptic number.

It is an amenable number.

87138269 is a deficient number, since it is larger than the sum of its proper divisors (1).

87138269 is an equidigital number, since it uses as much as digits as its factorization.

87138269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 87138269 is about 9334.7881068613. The cubic root of 87138269 is about 443.3393798837.

The spelling of 87138269 in words is "eighty-seven million, one hundred thirty-eight thousand, two hundred sixty-nine".