257871781440 has 2240 divisors, whose sum is σ = 1226802931200. Its totient is φ = 49877876736.

The previous prime is 257871781429. The next prime is 257871781451. The reversal of 257871781440 is 44187178752.

It is a happy number.

257871781440 is a `hidden beast` number, since 2 + 57 + 8 + 71 + 7 + 81 + 440 = 666.

It is an interprime number because it is at equal distance from previous prime (257871781429) and next prime (257871781451).

It is a tau number, because it is divible by the number of its divisors (2240).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 2365796106 + ... + 2365796214.

It is an arithmetic number, because the mean of its divisors is an integer number (547679880).

Almost surely, 2^257871781440 is an apocalyptic number.

257871781440 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 257871781440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (613401465600).

257871781440 is an abundant number, since it is smaller than the sum of its proper divisors (968931149760).

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

257871781440 is a wasteful number, since it uses less digits than its factorization.

257871781440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 3512320, while the sum is 54.

The spelling of 257871781440 in words is "two hundred fifty-seven billion, eight hundred seventy-one million, seven hundred eighty-one thousand, four hundred forty".