257279440 has 40 divisors (see below), whose sum is σ = 652556448. Its totient is φ = 93555840.

The previous prime is 257279431. The next prime is 257279441. The reversal of 257279440 is 44972752.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 257279393 and 257279402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257279441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145302 + ... + 147061.

Almost surely, 2^257279440 is an apocalyptic number.

257279440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

257279440 is an abundant number, since it is smaller than the sum of its proper divisors (395277008).

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

257279440 is a wasteful number, since it uses less digits than its factorization.

257279440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292387 (or 292381 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 40.

The square root of 257279440 is about 16039.9326681879. The cubic root of 257279440 is about 636.0164678040.

The spelling of 257279440 in words is "two hundred fifty-seven million, two hundred seventy-nine thousand, four hundred forty".