255700021 has 4 divisors (see below), whose sum is σ = 255895200. Its totient is φ = 255504844.

The previous prime is 255700019. The next prime is 255700057. The reversal of 255700021 is 120007552.

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 255700021 - 2¹ = 255700019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 255699965 and 255700001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255700001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95611 + ... + 98248.

It is an arithmetic number, because the mean of its divisors is an integer number (63973800).

Almost surely, 2^255700021 is an apocalyptic number.

It is an amenable number.

255700021 is a deficient number, since it is larger than the sum of its proper divisors (195179).

255700021 is a wasteful number, since it uses less digits than its factorization.

255700021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195178.

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 255700021 is about 15990.6229084423. The cubic root of 255700021 is about 634.7123097983.

Adding to 255700021 its reverse (120007552), we get a palindrome (375707573).

The spelling of 255700021 in words is "two hundred fifty-five million, seven hundred thousand, twenty-one".