821417 has 4 divisors (see below), whose sum is σ = 823440. Its totient is φ = 819396.

The previous prime is 821411. The next prime is 821441. The reversal of 821417 is 714128.

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 821417 - 2¹² = 817321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 821392 and 821401.

It is not an unprimeable number, because it can be changed into a prime (821411) 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, 167 + ... + 1292.

It is an arithmetic number, because the mean of its divisors is an integer number (205860).

2⁸²¹⁴¹⁷ is an apocalyptic number.

It is an amenable number.

821417 is a deficient number, since it is larger than the sum of its proper divisors (2023).

821417 is a wasteful number, since it uses less digits than its factorization.

821417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2022.

The product of its digits is 448, while the sum is 23.

The square root of 821417 is about 906.3205834582. The cubic root of 821417 is about 93.6528997608.

The spelling of 821417 in words is "eight hundred twenty-one thousand, four hundred seventeen".