821403612 has 48 divisors (see below), whose sum is σ = 2137330720. Its totient is φ = 272802816.

The previous prime is 821403599. The next prime is 821403643. The reversal of 821403612 is 216304128.

821403612 is a `hidden beast` number, since 8 + 2 + 1 + 40 + 3 + 612 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16188 + ... + 43644.

Almost surely, 2^821403612 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821403612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1068665360).

821403612 is an abundant number, since it is smaller than the sum of its proper divisors (1315927108).

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

821403612 is a wasteful number, since it uses less digits than its factorization.

821403612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27747 (or 27739 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 821403612 is about 28660.1397763514. The cubic root of 821403612 is about 936.5239095232.

The spelling of 821403612 in words is "eight hundred twenty-one million, four hundred three thousand, six hundred twelve".