1721993 has 16 divisors (see below), whose sum is σ = 2150400. Its totient is φ = 1342656.

The previous prime is 1721983. The next prime is 1722013. The reversal of 1721993 is 3991271.

It is a happy number.

It is not a de Polignac number, because 1721993 - 2¹⁸ = 1459849 is a prime.

It is a Curzon number.

It is a nialpdrome in base 8.

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 polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11483 + ... + 11631.

It is an arithmetic number, because the mean of its divisors is an integer number (134400).

2^1721993 is an apocalyptic number.

1721993 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1721993 is a deficient number, since it is larger than the sum of its proper divisors (428407).

1721993 is a wasteful number, since it uses less digits than its factorization.

1721993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296.

The product of its digits is 3402, while the sum is 32.

The square root of 1721993 is about 1312.2473090085. The cubic root of 1721993 is about 119.8607876358.

The spelling of 1721993 in words is "one million, seven hundred twenty-one thousand, nine hundred ninety-three".