2178320257 has 4 divisors (see below), whose sum is σ = 2209000896. Its totient is φ = 2147639620.

The previous prime is 2178320213. The next prime is 2178320371. The reversal of 2178320257 is 7520238712.

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.

It is a cyclic number.

It is not a de Polignac number, because 2178320257 - 2³¹ = 30836609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2178326257) 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, 15340213 + ... + 15340354.

It is an arithmetic number, because the mean of its divisors is an integer number (552250224).

Almost surely, 2^2178320257 is an apocalyptic number.

It is an amenable number.

2178320257 is a deficient number, since it is larger than the sum of its proper divisors (30680639).

2178320257 is an equidigital number, since it uses as much as digits as its factorization.

2178320257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30680638.

The product of its (nonzero) digits is 47040, while the sum is 37.

The square root of 2178320257 is about 46672.4785821366. The cubic root of 2178320257 is about 1296.3051409679.

Adding to 2178320257 its reverse (7520238712), we get a palindrome (9698558969).

The spelling of 2178320257 in words is "two billion, one hundred seventy-eight million, three hundred twenty thousand, two hundred fifty-seven".