1240640 has 28 divisors (see below), whose sum is σ = 2955036. Its totient is φ = 496128.

The previous prime is 1240637. The next prime is 1240667. The reversal of 1240640 is 460421.

It can be written as a sum of positive squares in 2 ways, for example, as 379456 + 861184 = 616^2 + 928^2 .

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1619 + ... + 2258.

It is an arithmetic number, because the mean of its divisors is an integer number (105537).

2^1240640 is an apocalyptic number.

1240640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1240640 is an abundant number, since it is smaller than the sum of its proper divisors (1714396).

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

1240640 is an equidigital number, since it uses as much as digits as its factorization.

1240640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3894 (or 3884 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 1240640 is about 1113.8402039790. The cubic root of 1240640 is about 107.4521871383.

The spelling of 1240640 in words is "one million, two hundred forty thousand, six hundred forty".