821425 has 24 divisors (see below), whose sum is σ = 1160640. Its totient is φ = 571200.

The previous prime is 821411. The next prime is 821441. The reversal of 821425 is 524128.

It is not a de Polignac number, because 821425 - 2⁷ = 821297 is a prime.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 821396 and 821405.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7924 + ... + 8026.

It is an arithmetic number, because the mean of its divisors is an integer number (48360).

2⁸²¹⁴²⁵ is an apocalyptic number.

It is an amenable number.

821425 is a deficient number, since it is larger than the sum of its proper divisors (339215).

821425 is a wasteful number, since it uses less digits than its factorization.

821425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 148 counting only the distinct ones).

The product of its digits is 640, while the sum is 22.

The square root of 821425 is about 906.3249968968. The cubic root of 821425 is about 93.6532037967.

The spelling of 821425 in words is "eight hundred twenty-one thousand, four hundred twenty-five".