256601980 has 24 divisors (see below), whose sum is σ = 539165088. Its totient is φ = 102583488.

The previous prime is 256601971. The next prime is 256601981. The reversal of 256601980 is 89106652.

It is a super-2 number, since 2×256601980² = 131689152279840800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256601981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69337 + ... + 72943.

It is an arithmetic number, because the mean of its divisors is an integer number (22465212).

Almost surely, 2^256601980 is an apocalyptic number.

256601980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256601980 is an abundant number, since it is smaller than the sum of its proper divisors (282563108).

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

256601980 is a wasteful number, since it uses less digits than its factorization.

256601980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7173 (or 7171 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 256601980 is about 16018.8008290259. The cubic root of 256601980 is about 635.4577310211.

The spelling of 256601980 in words is "two hundred fifty-six million, six hundred one thousand, nine hundred eighty".