255780861 has 32 divisors (see below), whose sum is σ = 430645248. Its totient is φ = 131577600.

The previous prime is 255780853. The next prime is 255780881. The reversal of 255780861 is 168087552.

It is not a de Polignac number, because 255780861 - 2³ = 255780853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255780821) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7365 + ... + 23786.

It is an arithmetic number, because the mean of its divisors is an integer number (13457664).

Almost surely, 2^255780861 is an apocalyptic number.

255780861 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

255780861 is a deficient number, since it is larger than the sum of its proper divisors (174864387).

255780861 is a wasteful number, since it uses less digits than its factorization.

255780861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31201.

The product of its (nonzero) digits is 134400, while the sum is 42.

The square root of 255780861 is about 15993.1504401103. The cubic root of 255780861 is about 634.7791912122.

The spelling of 255780861 in words is "two hundred fifty-five million, seven hundred eighty thousand, eight hundred sixty-one".