1005421 has 4 divisors (see below), whose sum is σ = 1008000.
Its totient is φ = 1002844.
The previous prime is 1005413. The next prime is 1005427. The reversal of 1005421 is 1245001.
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 1005421 - 23 = 1005413 is a prime.
It is a Duffinian number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1005427) 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, 571 + ... + 1528.
It is an arithmetic number, because the mean of its divisors is an integer number (252000).
It is a 390-hyperperfect number.
21005421 is an apocalyptic number.
It is an amenable number.
1005421 is a deficient number, since it is larger than the sum of its proper divisors (2579).
1005421 is an equidigital number, since it uses as much as digits as its factorization.
1005421 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 2578.
The product of its (nonzero) digits is 40, while the sum is 13.
The square root of 1005421 is about 1002.7068365180.
The cubic root of 1005421 is about 100.1803744549.
The spelling of 1005421 in words is "one million, five thousand, four hundred twenty-one".