138455987 has 2 divisors, whose sum is σ = 138455988. Its totient is φ = 138455986.

The previous prime is 138455959. The next prime is 138456011. The reversal of 138455987 is 789554831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138455987 - 2¹⁴ = 138439603 is a prime.

It is a super-2 number, since 2×138455987² = 38340120672288338, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (138455087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69227993 + 69227994.

It is an arithmetic number, because the mean of its divisors is an integer number (69227994).

Almost surely, 2^138455987 is an apocalyptic number.

138455987 is a deficient number, since it is larger than the sum of its proper divisors (1).

138455987 is an equidigital number, since it uses as much as digits as its factorization.

138455987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1209600, while the sum is 50.

The square root of 138455987 is about 11766.7322141706. The cubic root of 138455987 is about 517.3334736116. Note that the first 3 decimals are identical.

The spelling of 138455987 in words is "one hundred thirty-eight million, four hundred fifty-five thousand, nine hundred eighty-seven".