821685612 has 24 divisors (see below), whose sum is σ = 2091563712. Its totient is φ = 248995600.

The previous prime is 821685607. The next prime is 821685617. The reversal of 821685612 is 216586128.

It is an interprime number because it is at equal distance from previous prime (821685607) and next prime (821685617).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (821685617) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3112314 + ... + 3112577.

It is an arithmetic number, because the mean of its divisors is an integer number (87148488).

Almost surely, 2^821685612 is an apocalyptic number.

It is an amenable number.

821685612 is an abundant number, since it is smaller than the sum of its proper divisors (1269878100).

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

821685612 is a wasteful number, since it uses less digits than its factorization.

821685612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6224909 (or 6224907 counting only the distinct ones).

The product of its digits is 46080, while the sum is 39.

The square root of 821685612 is about 28665.0590789553. The cubic root of 821685612 is about 936.6310714273.

The spelling of 821685612 in words is "eight hundred twenty-one million, six hundred eighty-five thousand, six hundred twelve".