255796721 has 4 divisors (see below), whose sum is σ = 256143600. Its totient is φ = 255449844.

The previous prime is 255796711. The next prime is 255796727. The reversal of 255796721 is 127697552.

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 255796721 - 2⁶ = 255796657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (255796727) 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, 172331 + ... + 173808.

It is an arithmetic number, because the mean of its divisors is an integer number (64035900).

Almost surely, 2^255796721 is an apocalyptic number.

It is an amenable number.

255796721 is a deficient number, since it is larger than the sum of its proper divisors (346879).

255796721 is an equidigital number, since it uses as much as digits as its factorization.

255796721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346878.

The product of its digits is 264600, while the sum is 44.

The square root of 255796721 is about 15993.6462696910. The cubic root of 255796721 is about 634.7923110235.

The spelling of 255796721 in words is "two hundred fifty-five million, seven hundred ninety-six thousand, seven hundred twenty-one".