821801862 has 160 divisors (see below), whose sum is σ = 2278222848. Its totient is φ = 216048384.

The previous prime is 821801831. The next prime is 821801863. The reversal of 821801862 is 268108128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821801863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 905613 + ... + 906519.

Almost surely, 2^821801862 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821801862, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1139111424).

821801862 is an abundant number, since it is smaller than the sum of its proper divisors (1456420986).

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

821801862 is a wasteful number, since it uses less digits than its factorization.

821801862 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992 (or 983 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 821801862 is about 28667.0867372323. The cubic root of 821801862 is about 936.6752400752.

The spelling of 821801862 in words is "eight hundred twenty-one million, eight hundred one thousand, eight hundred sixty-two".