4257640 has 16 divisors (see below), whose sum is σ = 9579780. Its totient is φ = 1703040.

The previous prime is 4257613. The next prime is 4257641. The reversal of 4257640 is 467524.

It can be written as a sum of positive squares in 2 ways, for example, as 3541924 + 715716 = 1882^2 + 846^2 .

It is a junction number, because it is equal to n+sod(n) for n = 4257599 and 4257608.

It is not an unprimeable number, because it can be changed into a prime (4257641) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 53181 + ... + 53260.

Almost surely, 2^4257640 is an apocalyptic number.

4257640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

4257640 is an abundant number, since it is smaller than the sum of its proper divisors (5322140).

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

4257640 is a wasteful number, since it uses less digits than its factorization.

4257640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106452 (or 106448 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 28.

The square root of 4257640 is about 2063.4049529843. The cubic root of 4257640 is about 162.0775932717.

The spelling of 4257640 in words is "four million, two hundred fifty-seven thousand, six hundred forty".