139505887 has 4 divisors (see below), whose sum is σ = 139731880. Its totient is φ = 139279896.

The previous prime is 139505881. The next prime is 139505909. The reversal of 139505887 is 788505931.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 139505887 - 2²³ = 131117279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139505881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112068 + ... + 113305.

It is an arithmetic number, because the mean of its divisors is an integer number (34932970).

Almost surely, 2^139505887 is an apocalyptic number.

139505887 is a deficient number, since it is larger than the sum of its proper divisors (225993).

139505887 is an equidigital number, since it uses as much as digits as its factorization.

139505887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225992.

The product of its (nonzero) digits is 302400, while the sum is 46.

The square root of 139505887 is about 11811.2610249710. The cubic root of 139505887 is about 518.6378141880.

The spelling of 139505887 in words is "one hundred thirty-nine million, five hundred five thousand, eight hundred eighty-seven".