256021560 has 160 divisors (see below), whose sum is σ = 888624000. Its totient is φ = 66044160.

The previous prime is 256021531. The next prime is 256021603. The reversal of 256021560 is 65120652.

256021560 is a `hidden beast` number, since 2 + 5 + 602 + 1 + 56 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 99166 + ... + 101714.

It is an arithmetic number, because the mean of its divisors is an integer number (5553900).

Almost surely, 2^256021560 is an apocalyptic number.

256021560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256021560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (444312000).

256021560 is an abundant number, since it is smaller than the sum of its proper divisors (632602440).

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

256021560 is a wasteful number, since it uses less digits than its factorization.

256021560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2603 (or 2590 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 256021560 is about 16000.6737358150. The cubic root of 256021560 is about 634.9782454779.

The spelling of 256021560 in words is "two hundred fifty-six million, twenty-one thousand, five hundred sixty".