139942689 has 4 divisors (see below), whose sum is σ = 186590256. Its totient is φ = 93295124.

The previous prime is 139942681. The next prime is 139942729. The reversal of 139942689 is 986249931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 986249931 = 3 ⋅328749977.

It is a cyclic number.

It is not a de Polignac number, because 139942689 - 2³ = 139942681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (139942681) 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, 23323779 + ... + 23323784.

It is an arithmetic number, because the mean of its divisors is an integer number (46647564).

Almost surely, 2^139942689 is an apocalyptic number.

It is an amenable number.

139942689 is a deficient number, since it is larger than the sum of its proper divisors (46647567).

139942689 is an equidigital number, since it uses as much as digits as its factorization.

139942689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46647566.

The product of its digits is 839808, while the sum is 51.

The square root of 139942689 is about 11829.7374865210. The cubic root of 139942689 is about 519.1785464599.

The spelling of 139942689 in words is "one hundred thirty-nine million, nine hundred forty-two thousand, six hundred eighty-nine".