1244640 has 48 divisors (see below), whose sum is σ = 3922128. Its totient is φ = 331776.

The previous prime is 1244629. The next prime is 1244647. The reversal of 1244640 is 464421.

It is a tau number, because it is divible by the number of its divisors (48).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1244647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 817 + ... + 1776.

It is an arithmetic number, because the mean of its divisors is an integer number (81711).

2^1244640 is an apocalyptic number.

1244640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1244640 is an abundant number, since it is smaller than the sum of its proper divisors (2677488).

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

1244640 is a wasteful number, since it uses less digits than its factorization.

1244640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2611 (or 2603 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 1244640 is about 1115.6343487003. The cubic root of 1244640 is about 107.5675436351.

The spelling of 1244640 in words is "one million, two hundred forty-four thousand, six hundred forty".