1299840 has 64 divisors (see below), whose sum is σ = 4149360. Its totient is φ = 346112.

The previous prime is 1299833. The next prime is 1299841. The reversal of 1299840 is 489921.

1299840 = T₃₇₁ + T₃₇₂ + ... + T₃₈₈.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1299841) 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, 1582 + ... + 2258.

2^1299840 is an apocalyptic number.

1299840 is a gapful number since it is divisible by the number (10) 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 1299840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2074680).

1299840 is an abundant number, since it is smaller than the sum of its proper divisors (2849520).

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

1299840 is an equidigital number, since it uses as much as digits as its factorization.

1299840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 1299840 is about 1140.1052582985. The cubic root of 1299840 is about 109.1348106131.

The spelling of 1299840 in words is "one million, two hundred ninety-nine thousand, eight hundred forty".