155644639 has 12 divisors (see below), whose sum is σ = 166608576. Its totient is φ = 144898752.

The previous prime is 155644633. The next prime is 155644667. The reversal of 155644639 is 936446551.

It is not a de Polignac number, because 155644639 - 2¹³ = 155636447 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 155644595 and 155644604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155644633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 179922 + ... + 180784.

It is an arithmetic number, because the mean of its divisors is an integer number (13884048).

Almost surely, 2^155644639 is an apocalyptic number.

155644639 is a deficient number, since it is larger than the sum of its proper divisors (10963937).

155644639 is an equidigital number, since it uses as much as digits as its factorization.

155644639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1086 (or 983 counting only the distinct ones).

The product of its digits is 388800, while the sum is 43.

The square root of 155644639 is about 12475.7620608923. The cubic root of 155644639 is about 537.9121932126.

The spelling of 155644639 in words is "one hundred fifty-five million, six hundred forty-four thousand, six hundred thirty-nine".