4256640 has 96 divisors (see below), whose sum is σ = 14718600. Its totient is φ = 1133568.

The previous prime is 4256639. The next prime is 4256653. The reversal of 4256640 is 466524.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5391 + ... + 6129.

Almost surely, 2^4256640 is an apocalyptic number.

4256640 is a gapful number since it is divisible by the number (40) 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 4256640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7359300).

4256640 is an abundant number, since it is smaller than the sum of its proper divisors (10461960).

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

4256640 is a wasteful number, since it uses less digits than its factorization.

4256640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764 (or 749 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 4256640 is about 2063.1626208324. The cubic root of 4256640 is about 162.0649031206.

The spelling of 4256640 in words is "four million, two hundred fifty-six thousand, six hundred forty".