257438720 has 176 divisors, whose sum is σ = 771113088. Its totient is φ = 80117760.

The previous prime is 257438659. The next prime is 257438729. The reversal of 257438720 is 27834752.

It is a tau number, because it is divible by the number of its divisors (176).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257438729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 393914 + ... + 394566.

Almost surely, 2^257438720 is an apocalyptic number.

257438720 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 257438720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (385556544).

257438720 is an abundant number, since it is smaller than the sum of its proper divisors (513674368).

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

257438720 is a wasteful number, since it uses less digits than its factorization.

257438720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696 (or 678 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 38.

The square root of 257438720 is about 16044.8970080833. The cubic root of 257438720 is about 636.1476919242.

The spelling of 257438720 in words is "two hundred fifty-seven million, four hundred thirty-eight thousand, seven hundred twenty".