256666410 has 432 divisors, whose sum is σ = 943743528. Its totient is φ = 47900160.

The previous prime is 256666409. The next prime is 256666427. The reversal of 256666410 is 14666652.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 211789809 + 44876601 = 14553^2 + 6699^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 6936912 + ... + 6936948.

Almost surely, 2^256666410 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256666410, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (471871764).

256666410 is an abundant number, since it is smaller than the sum of its proper divisors (687077118).

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

256666410 is a wasteful number, since it uses less digits than its factorization.

256666410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 256666410 is about 16020.8117771853. The cubic root of 256666410 is about 635.5109121063.

It can be divided in two parts, 256 and 666410, that added together give a palindrome (666666).

The spelling of 256666410 in words is "two hundred fifty-six million, six hundred sixty-six thousand, four hundred ten".