1825721 has 4 divisors (see below), whose sum is σ = 1833600. Its totient is φ = 1817844.

The previous prime is 1825711. The next prime is 1825723. The reversal of 1825721 is 1275281.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1825721 - 2¹⁸ = 1563577 is a prime.

It is a super-4 number, since 4×1825721⁴ (a number of 26 digits) contains 4444 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1825723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3581 + ... + 4058.

It is an arithmetic number, because the mean of its divisors is an integer number (458400).

2^1825721 is an apocalyptic number.

It is an amenable number.

1825721 is a deficient number, since it is larger than the sum of its proper divisors (7879).

1825721 is an equidigital number, since it uses as much as digits as its factorization.

1825721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7878.

The product of its digits is 1120, while the sum is 26.

The square root of 1825721 is about 1351.1924363317. The cubic root of 1825721 is about 122.2207103884.

The spelling of 1825721 in words is "one million, eight hundred twenty-five thousand, seven hundred twenty-one".