257420 has 24 divisors (see below), whose sum is σ = 552048. Its totient is φ = 100800.

The previous prime is 257407. The next prime is 257437. The reversal of 257420 is 24752.

257420 = T₆₁ + T₆₂ + ... + T₁₂₀.

257420 is nontrivially palindromic in base 15.

It is a Smith number, since the sum of its digits (20) 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 (20).

It is a junction number, because it is equal to n+sod(n) for n = 257392 and 257401.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1115 + ... + 1325.

It is an arithmetic number, because the mean of its divisors is an integer number (23002).

2²⁵⁷⁴²⁰ is an apocalyptic number.

257420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

257420 is an abundant number, since it is smaller than the sum of its proper divisors (294628).

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

257420 is a wasteful number, since it uses less digits than its factorization.

257420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281 (or 279 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 20.

The square root of 257420 is about 507.3657457890. The cubic root of 257420 is about 63.6132272108.

The spelling of 257420 in words is "two hundred fifty-seven thousand, four hundred twenty".