257918940 has 72 divisors (see below), whose sum is σ = 788140080. Its totient is φ = 68269824.

The previous prime is 257918909. The next prime is 257918959. The reversal of 257918940 is 49819752.

It is a super-2 number, since 2×257918940² = 133044359221447200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) 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 (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19431 + ... + 29889.

It is an arithmetic number, because the mean of its divisors is an integer number (10946390).

Almost surely, 2^257918940 is an apocalyptic number.

257918940 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 257918940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (394070040).

257918940 is an abundant number, since it is smaller than the sum of its proper divisors (530221140).

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

257918940 is a wasteful number, since it uses less digits than its factorization.

257918940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10611 (or 10606 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 257918940 is about 16059.8549183982. The cubic root of 257918940 is about 636.5429977656.

The spelling of 257918940 in words is "two hundred fifty-seven million, nine hundred eighteen thousand, nine hundred forty".