257048640 has 280 divisors, whose sum is σ = 938247552. Its totient is φ = 66769920.

The previous prime is 257048633. The next prime is 257048641. The reversal of 257048640 is 46840752.

257048640 is a `hidden beast` number, since 2 + 5 + 7 + 0 + 4 + 8 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 257048595 and 257048604.

It is not an unprimeable number, because it can be changed into a prime (257048641) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1218135 + ... + 1218345.

Almost surely, 2^257048640 is an apocalyptic number.

257048640 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 257048640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (469123776).

257048640 is an abundant number, since it is smaller than the sum of its proper divisors (681198912).

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

257048640 is a wasteful number, since it uses less digits than its factorization.

257048640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287 (or 268 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 257048640 is about 16032.7365100285. The cubic root of 257048640 is about 635.8262252186.

The spelling of 257048640 in words is "two hundred fifty-seven million, forty-eight thousand, six hundred forty".