1721943 has 12 divisors (see below), whose sum is σ = 2554968. Its totient is φ = 1116720.

The previous prime is 1721927. The next prime is 1721983. The reversal of 1721943 is 3491271.

It is not a de Polignac number, because 1721943 - 2⁴ = 1721927 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1721903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2253 + ... + 2918.

It is an arithmetic number, because the mean of its divisors is an integer number (212914).

2^1721943 is an apocalyptic number.

1721943 is a deficient number, since it is larger than the sum of its proper divisors (833025).

1721943 is a wasteful number, since it uses less digits than its factorization.

1721943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5214 (or 5211 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 1721943 is about 1312.2282575833. The cubic root of 1721943 is about 119.8596275271.

The spelling of 1721943 in words is "one million, seven hundred twenty-one thousand, nine hundred forty-three".