256137216 has 96 divisors (see below), whose sum is σ = 698181120. Its totient is φ = 83468288.

The previous prime is 256137173. The next prime is 256137229. The reversal of 256137216 is 612731652.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 288325 + ... + 289211.

It is an arithmetic number, because the mean of its divisors is an integer number (7272720).

Almost surely, 2^256137216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256137216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349090560).

256137216 is an abundant number, since it is smaller than the sum of its proper divisors (442043904).

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

256137216 is an equidigital number, since it uses as much as digits as its factorization.

256137216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 959 (or 939 counting only the distinct ones).

The product of its digits is 15120, while the sum is 33.

The square root of 256137216 is about 16004.2874255619. The cubic root of 256137216 is about 635.0738467861.

Adding to 256137216 its reverse (612731652), we get a palindrome (868868868).

The spelling of 256137216 in words is "two hundred fifty-six million, one hundred thirty-seven thousand, two hundred sixteen".