1821007 has 4 divisors (see below), whose sum is σ = 1863400. Its totient is φ = 1778616.

The previous prime is 1820999. The next prime is 1821013. The reversal of 1821007 is 7001281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7001281 = 7 ⋅1000183.

It is a cyclic number.

It is not a de Polignac number, because 1821007 - 2³ = 1820999 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21132 + ... + 21217.

It is an arithmetic number, because the mean of its divisors is an integer number (465850).

2^1821007 is an apocalyptic number.

1821007 is a deficient number, since it is larger than the sum of its proper divisors (42393).

1821007 is an equidigital number, since it uses as much as digits as its factorization.

1821007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42392.

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 1821007 is about 1349.4469237432. The cubic root of 1821007 is about 122.1154286921.

Adding to 1821007 its reverse (7001281), we get a palindrome (8822288).

It can be divided in two parts, 18 and 21007, that added together give a square (21025 = 145²).

The spelling of 1821007 in words is "one million, eight hundred twenty-one thousand, seven".