1640256 has 28 divisors (see below), whose sum is σ = 4340352. Its totient is φ = 546688.

The previous prime is 1640231. The next prime is 1640263. The reversal of 1640256 is 6520461.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4080 + ... + 4463.

2^1640256 is an apocalyptic number.

1640256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1640256 is an abundant number, since it is smaller than the sum of its proper divisors (2700096).

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

1640256 is an equidigital number, since it uses as much as digits as its factorization.

1640256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8558 (or 8548 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 1640256 is about 1280.7247947939. The cubic root of 1640256 is about 117.9335065385.

The spelling of 1640256 in words is "one million, six hundred forty thousand, two hundred fifty-six".