257021706240 has 504 divisors, whose sum is σ = 961837334640. Its totient is φ = 63115886592.

The previous prime is 257021706217. The next prime is 257021706241. The reversal of 257021706240 is 42607120752.

It is a happy number.

257021706240 is a `hidden beast` number, since 2 + 5 + 7 + 0 + 21 + 7 + 0 + 624 + 0 = 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 = 257021706195 and 257021706204.

It is not an unprimeable number, because it can be changed into a prime (257021706241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 613416751 + ... + 613417169.

It is an arithmetic number, because the mean of its divisors is an integer number (1908407410).

Almost surely, 2^257021706240 is an apocalyptic number.

257021706240 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 257021706240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (480918667320).

257021706240 is an abundant number, since it is smaller than the sum of its proper divisors (704815628400).

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

257021706240 is an frugal number, since it uses more digits than its factorization.

257021706240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483 (or 442 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

Adding to 257021706240 its reverse (42607120752), we get a palindrome (299628826992).

The spelling of 257021706240 in words is "two hundred fifty-seven billion, twenty-one million, seven hundred six thousand, two hundred forty".