1321840 has 80 divisors (see below), whose sum is σ = 3499776. Its totient is φ = 460800.

The previous prime is 1321823. The next prime is 1321841. The reversal of 1321840 is 481231.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321841) 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, 32220 + ... + 32260.

2^1321840 is an apocalyptic number.

1321840 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 1321840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1749888).

1321840 is an abundant number, since it is smaller than the sum of its proper divisors (2177936).

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

1321840 is a wasteful number, since it uses less digits than its factorization.

1321840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 1321840 is about 1149.7130076676. The cubic root of 1321840 is about 109.7470773035.

The spelling of 1321840 in words is "one million, three hundred twenty-one thousand, eight hundred forty".