821680188 has 48 divisors (see below), whose sum is σ = 2193133824. Its totient is φ = 234552960.

The previous prime is 821680183. The next prime is 821680217. The reversal of 821680188 is 881086128.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821680183) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104656 + ... + 112232.

It is an arithmetic number, because the mean of its divisors is an integer number (45690288).

Almost surely, 2^821680188 is an apocalyptic number.

It is an amenable number.

821680188 is an abundant number, since it is smaller than the sum of its proper divisors (1371453636).

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

821680188 is a wasteful number, since it uses less digits than its factorization.

821680188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8882 (or 8880 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 42.

The square root of 821680188 is about 28664.9644688424. The cubic root of 821680188 is about 936.6290105019.

The spelling of 821680188 in words is "eight hundred twenty-one million, six hundred eighty thousand, one hundred eighty-eight".