155639839 has 4 divisors (see below), whose sum is σ = 161006760. Its totient is φ = 150272920.

The previous prime is 155639837. The next prime is 155639851. The reversal of 155639839 is 938936551.

It is a happy number.

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 155639839 - 2¹ = 155639837 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 155639792 and 155639801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155639837) 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, 2683417 + ... + 2683474.

It is an arithmetic number, because the mean of its divisors is an integer number (40251690).

Almost surely, 2^155639839 is an apocalyptic number.

155639839 is a deficient number, since it is larger than the sum of its proper divisors (5366921).

155639839 is an equidigital number, since it uses as much as digits as its factorization.

155639839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5366920.

The product of its digits is 874800, while the sum is 49.

The square root of 155639839 is about 12475.5696863911. The cubic root of 155639839 is about 537.9066635113.

The spelling of 155639839 in words is "one hundred fifty-five million, six hundred thirty-nine thousand, eight hundred thirty-nine".