256538100 has 144 divisors (see below), whose sum is σ = 913635968. Its totient is φ = 54120960.

The previous prime is 256538099. The next prime is 256538167. The reversal of 256538100 is 1835652.

It is a super-5 number, since 5×256538100⁵ (a number of 43 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 22602 + ... + 31998.

Almost surely, 2^256538100 is an apocalyptic number.

256538100 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 256538100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (456817984).

256538100 is an abundant number, since it is smaller than the sum of its proper divisors (657097868).

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

256538100 is a wasteful number, since it uses less digits than its factorization.

256538100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9434 (or 9427 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 256538100 is about 16016.8067978608. The cubic root of 256538100 is about 635.4049951214.

The spelling of 256538100 in words is "two hundred fifty-six million, five hundred thirty-eight thousand, one hundred".