257218068240 has 1280 divisors, whose sum is σ = 1097072640000. Its totient is φ = 54135889920.

The previous prime is 257218068229. The next prime is 257218068241. The reversal of 257218068240 is 42860812752.

257218068240 is a `hidden beast` number, since 2 + 572 + 18 + 0 + 68 + 2 + 4 + 0 = 666.

It is a super-2 number, since 2×257218068240² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (257218068241) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 1726295686 + ... + 1726295834.

It is an arithmetic number, because the mean of its divisors is an integer number (857088000).

Almost surely, 2^257218068240 is an apocalyptic number.

257218068240 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 257218068240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (548536320000).

257218068240 is an abundant number, since it is smaller than the sum of its proper divisors (839854571760).

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

257218068240 is a wasteful number, since it uses less digits than its factorization.

257218068240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 45.

The spelling of 257218068240 in words is "two hundred fifty-seven billion, two hundred eighteen million, sixty-eight thousand, two hundred forty".