1368721 has 4 divisors (see below), whose sum is σ = 1449252. Its totient is φ = 1288192.

The previous prime is 1368683. The next prime is 1368727. The reversal of 1368721 is 1278631.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 408321 + 960400 = 639^2 + 980^2 .

It is not a de Polignac number, because 1368721 - 2¹³ = 1360529 is a prime.

It is a Duffinian number.

1368721 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1368721.

It is not an unprimeable number, because it can be changed into a prime (1368727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40240 + ... + 40273.

It is an arithmetic number, because the mean of its divisors is an integer number (362313).

2^1368721 is an apocalyptic number.

It is an amenable number.

1368721 is a deficient number, since it is larger than the sum of its proper divisors (80531).

1368721 is an equidigital number, since it uses as much as digits as its factorization.

1368721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80530.

The product of its digits is 2016, while the sum is 28.

The square root of 1368721 is about 1169.9235017727. The cubic root of 1368721 is about 111.0294811177.

The spelling of 1368721 in words is "one million, three hundred sixty-eight thousand, seven hundred twenty-one".