1721231 has 4 divisors (see below), whose sum is σ = 1734912. Its totient is φ = 1707552.

The previous prime is 1721227. The next prime is 1721243. The reversal of 1721231 is 1321271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1321271 = 7 ⋅188753.

It is a cyclic number.

It is not a de Polignac number, because 1721231 - 2² = 1721227 is a prime.

It is a super-2 number, since 2×1721231² = 5925272310722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1721201) 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 3 ways as a sum of consecutive naturals, for example, 6650 + ... + 6903.

It is an arithmetic number, because the mean of its divisors is an integer number (433728).

2^1721231 is an apocalyptic number.

1721231 is a deficient number, since it is larger than the sum of its proper divisors (13681).

1721231 is a wasteful number, since it uses less digits than its factorization.

1721231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13680.

The product of its digits is 84, while the sum is 17.

The square root of 1721231 is about 1311.9569352688. The cubic root of 1721231 is about 119.8431051413.

The spelling of 1721231 in words is "one million, seven hundred twenty-one thousand, two hundred thirty-one".