1721868 has 12 divisors (see below), whose sum is σ = 4017720. Its totient is φ = 573952.

The previous prime is 1721857. The next prime is 1721887. The reversal of 1721868 is 8681271.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71733 + ... + 71756.

It is an arithmetic number, because the mean of its divisors is an integer number (334810).

2^1721868 is an apocalyptic number.

It is an amenable number.

1721868 is an abundant number, since it is smaller than the sum of its proper divisors (2295852).

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

1721868 is a wasteful number, since it uses less digits than its factorization.

1721868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143496 (or 143494 counting only the distinct ones).

The product of its digits is 5376, while the sum is 33.

The square root of 1721868 is about 1312.1996799268. The cubic root of 1721868 is about 119.8578873219.

The spelling of 1721868 in words is "one million, seven hundred twenty-one thousand, eight hundred sixty-eight".