139218887 has 2 divisors, whose sum is σ = 139218888. Its totient is φ = 139218886.

The previous prime is 139218883. The next prime is 139218889. The reversal of 139218887 is 788812931.

139218887 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 139218887 - 2² = 139218883 is a prime.

Together with 139218889, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139218883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69609443 + 69609444.

It is an arithmetic number, because the mean of its divisors is an integer number (69609444).

Almost surely, 2^139218887 is an apocalyptic number.

139218887 is a deficient number, since it is larger than the sum of its proper divisors (1).

139218887 is an equidigital number, since it uses as much as digits as its factorization.

139218887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 47.

The square root of 139218887 is about 11799.1053474405. The cubic root of 139218887 is about 518.2819122581.

The spelling of 139218887 in words is "one hundred thirty-nine million, two hundred eighteen thousand, eight hundred eighty-seven".