2557320321 has 4 divisors (see below), whose sum is σ = 3409760432. Its totient is φ = 1704880212.

The previous prime is 2557320317. The next prime is 2557320349. The reversal of 2557320321 is 1230237552.

It is a happy number.

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 not a de Polignac number, because 2557320321 - 2² = 2557320317 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2557320121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 426220051 + ... + 426220056.

It is an arithmetic number, because the mean of its divisors is an integer number (852440108).

Almost surely, 2^2557320321 is an apocalyptic number.

It is an amenable number.

2557320321 is a deficient number, since it is larger than the sum of its proper divisors (852440111).

2557320321 is an equidigital number, since it uses as much as digits as its factorization.

2557320321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852440110.

The product of its (nonzero) digits is 12600, while the sum is 30.

The square root of 2557320321 is about 50569.9547261019. The cubic root of 2557320321 is about 1367.5032795949.

Adding to 2557320321 its reverse (1230237552), we get a palindrome (3787557873).

The spelling of 2557320321 in words is "two billion, five hundred fifty-seven million, three hundred twenty thousand, three hundred twenty-one".