821442825 has 36 divisors (see below), whose sum is σ = 1681483648. Its totient is φ = 375516000.

The previous prime is 821442779. The next prime is 821442833. The reversal of 821442825 is 528244128.

It is not a de Polignac number, because 821442825 - 2¹² = 821438729 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 821442825.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 259201 + ... + 262350.

Almost surely, 2^821442825 is an apocalyptic number.

It is an amenable number.

821442825 is an abundant number, since it is smaller than the sum of its proper divisors (860040823).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821442825 is a wasteful number, since it uses less digits than its factorization.

821442825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521574 (or 521566 counting only the distinct ones).

The product of its digits is 40960, while the sum is 36.

The square root of 821442825 is about 28660.8238716196. The cubic root of 821442825 is about 936.5388121960.

The spelling of 821442825 in words is "eight hundred twenty-one million, four hundred forty-two thousand, eight hundred twenty-five".