2157555439 has 4 divisors (see below), whose sum is σ = 2323521256. Its totient is φ = 1991589624.

The previous prime is 2157555403. The next prime is 2157555473. The reversal of 2157555439 is 9345557512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2157555439 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 (2157505439) 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 3 ways as a sum of consecutive naturals, for example, 82982889 + ... + 82982914.

It is an arithmetic number, because the mean of its divisors is an integer number (580880314).

Almost surely, 2^2157555439 is an apocalyptic number.

2157555439 is a deficient number, since it is larger than the sum of its proper divisors (165965817).

2157555439 is a wasteful number, since it uses less digits than its factorization.

2157555439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165965816.

The product of its digits is 945000, while the sum is 46.

The square root of 2157555439 is about 46449.4934202732. The cubic root of 2157555439 is about 1292.1729774360.

The spelling of 2157555439 in words is "two billion, one hundred fifty-seven million, five hundred fifty-five thousand, four hundred thirty-nine".