257006646 has 144 divisors (see below), whose sum is σ = 675301536. Its totient is φ = 69848064.

The previous prime is 257006611. The next prime is 257006653. The reversal of 257006646 is 646600752.

257006646 is a `hidden beast` number, since 2 + 5 + 7 + 0 + 0 + 6 + 646 = 666.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 257006646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4849156 + ... + 4849208.

It is an arithmetic number, because the mean of its divisors is an integer number (4689594).

Almost surely, 2^257006646 is an apocalyptic number.

257006646 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 257006646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (337650768).

257006646 is an abundant number, since it is smaller than the sum of its proper divisors (418294890).

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

257006646 is a wasteful number, since it uses less digits than its factorization.

257006646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 257006646 is about 16031.4268235862. The cubic root of 257006646 is about 635.7915983860.

The spelling of 257006646 in words is "two hundred fifty-seven million, six thousand, six hundred forty-six".