821425381 has 12 divisors (see below), whose sum is σ = 981367072. Its totient is φ = 673463736.

The previous prime is 821425351. The next prime is 821425393. The reversal of 821425381 is 183524128.

It is a happy number.

It is not a de Polignac number, because 821425381 - 2⁵ = 821425349 is a prime.

It is a super-2 number, since 2×821425381² = 1349479313101990322, which contains 22 as substring.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821425351) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107211 + ... + 114616.

Almost surely, 2^821425381 is an apocalyptic number.

It is an amenable number.

821425381 is a deficient number, since it is larger than the sum of its proper divisors (159941691).

821425381 is a wasteful number, since it uses less digits than its factorization.

821425381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221880 (or 221857 counting only the distinct ones).

The product of its digits is 15360, while the sum is 34.

The square root of 821425381 is about 28660.5195521644. The cubic root of 821425381 is about 936.5321827637.

The spelling of 821425381 in words is "eight hundred twenty-one million, four hundred twenty-five thousand, three hundred eighty-one".