256356820 has 12 divisors (see below), whose sum is σ = 538349364. Its totient is φ = 102542720.

The previous prime is 256356811. The next prime is 256356823. The reversal of 256356820 is 28653652.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 54375876 + 201980944 = 7374^2 + 14212^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 256356820.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256356823) 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, 6408901 + ... + 6408940.

It is an arithmetic number, because the mean of its divisors is an integer number (44862447).

Almost surely, 2^256356820 is an apocalyptic number.

256356820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256356820 is an abundant number, since it is smaller than the sum of its proper divisors (281992544).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256356820 is a wasteful number, since it uses less digits than its factorization.

256356820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12817850 (or 12817848 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 37.

The square root of 256356820 is about 16011.1467421918. The cubic root of 256356820 is about 635.2552923938.

The spelling of 256356820 in words is "two hundred fifty-six million, three hundred fifty-six thousand, eight hundred twenty".