255612166021 has 4 divisors (see below), whose sum is σ = 260435037132. Its totient is φ = 250789294912.

The previous prime is 255612165979. The next prime is 255612166037. The reversal of 255612166021 is 120661216552.

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

It can be written as a sum of positive squares in 2 ways, for example, as 212441715396 + 43170450625 = 460914^2 + 207775^2 .

It is a cyclic number.

It is not a de Polignac number, because 255612166021 - 2¹¹ = 255612163973 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 (255612166421) 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, 2411435476 + ... + 2411435581.

It is an arithmetic number, because the mean of its divisors is an integer number (65108759283).

Almost surely, 2^255612166021 is an apocalyptic number.

It is an amenable number.

255612166021 is a deficient number, since it is larger than the sum of its proper divisors (4822871111).

255612166021 is an equidigital number, since it uses as much as digits as its factorization.

255612166021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4822871110.

The product of its (nonzero) digits is 43200, while the sum is 37.

The spelling of 255612166021 in words is "two hundred fifty-five billion, six hundred twelve million, one hundred sixty-six thousand, twenty-one".