139031987 has 16 divisors (see below), whose sum is σ = 154897920. Its totient is φ = 124185600.

The previous prime is 139031983. The next prime is 139031999. The reversal of 139031987 is 789130931.

139031987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 139031987 - 2² = 139031983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139031983) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28787 + ... + 33267.

It is an arithmetic number, because the mean of its divisors is an integer number (9681120).

Almost surely, 2^139031987 is an apocalyptic number.

139031987 is a deficient number, since it is larger than the sum of its proper divisors (15865933).

139031987 is a wasteful number, since it uses less digits than its factorization.

139031987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4594.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 139031987 is about 11791.1825954821. The cubic root of 139031987 is about 518.0498789196.

The spelling of 139031987 in words is "one hundred thirty-nine million, thirty-one thousand, nine hundred eighty-seven".