1721368 has 32 divisors (see below), whose sum is σ = 3640320. Its totient is φ = 756000.

The previous prime is 1721347. The next prime is 1721371. The reversal of 1721368 is 8631271.

It is a nialpdrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2413 + ... + 3043.

It is an arithmetic number, because the mean of its divisors is an integer number (113760).

2^1721368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1721368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1820160).

1721368 is an abundant number, since it is smaller than the sum of its proper divisors (1918952).

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

1721368 is a wasteful number, since it uses less digits than its factorization.

1721368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 679 (or 675 counting only the distinct ones).

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

The square root of 1721368 is about 1312.0091463096. The cubic root of 1721368 is about 119.8462846622.

Subtracting 1721368 from its reverse (8631271), we obtain a triangular number (6909903 = T₃₇₁₇).

It can be divided in two parts, 172 and 1368, that added together give a triangular number (1540 = T₅₅).

The spelling of 1721368 in words is "one million, seven hundred twenty-one thousand, three hundred sixty-eight".