255220861 has 24 divisors (see below), whose sum is σ = 307964160. Its totient is φ = 210672000.

The previous prime is 255220837. The next prime is 255220877. The reversal of 255220861 is 168022552.

It is not a de Polignac number, because 255220861 - 2⁹ = 255220349 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255220831) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 608910 + ... + 609328.

It is an arithmetic number, because the mean of its divisors is an integer number (12831840).

Almost surely, 2^255220861 is an apocalyptic number.

It is an amenable number.

255220861 is a deficient number, since it is larger than the sum of its proper divisors (52743299).

255220861 is a wasteful number, since it uses less digits than its factorization.

255220861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 865 (or 858 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 31.

The square root of 255220861 is about 15975.6333520772. The cubic root of 255220861 is about 634.3155963400.

The spelling of 255220861 in words is "two hundred fifty-five million, two hundred twenty thousand, eight hundred sixty-one".