255305621 has 4 divisors (see below), whose sum is σ = 255338700. Its totient is φ = 255272544.

The previous prime is 255305591. The next prime is 255305623. The reversal of 255305621 is 126503552.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 164198596 + 91107025 = 12814^2 + 9545^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-255305621 is a prime.

It is a super-2 number, since 2×255305621² = 130361920228391282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255305623) 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, 1865 + ... + 22673.

It is an arithmetic number, because the mean of its divisors is an integer number (63834675).

Almost surely, 2^255305621 is an apocalyptic number.

It is an amenable number.

255305621 is a deficient number, since it is larger than the sum of its proper divisors (33079).

255305621 is a wasteful number, since it uses less digits than its factorization.

255305621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33078.

The product of its (nonzero) digits is 9000, while the sum is 29.

The square root of 255305621 is about 15978.2859218378. The cubic root of 255305621 is about 634.3858082590.

The spelling of 255305621 in words is "two hundred fifty-five million, three hundred five thousand, six hundred twenty-one".