1298640 has 80 divisors (see below), whose sum is σ = 4606848. Its totient is φ = 296448.

The previous prime is 1298617. The next prime is 1298641. The reversal of 1298640 is 468921.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1298598 and 1298607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1298641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1294 + ... + 2066.

2^1298640 is an apocalyptic number.

1298640 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 1298640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2303424).

1298640 is an abundant number, since it is smaller than the sum of its proper divisors (3308208).

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

1298640 is a wasteful number, since it uses less digits than its factorization.

1298640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 796 (or 790 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 1298640 is about 1139.5788695830. The cubic root of 1298640 is about 109.1012161979.

The spelling of 1298640 in words is "one million, two hundred ninety-eight thousand, six hundred forty".