823869640 has 288 divisors, whose sum is σ = 2351865600. Its totient is φ = 258508800.

The previous prime is 823869581. The next prime is 823869647. The reversal of 823869640 is 46968328.

It is a happy number.

It is a super-2 number, since 2×823869640² = 1357522367427459200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (823869647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 26576425 + ... + 26576455.

It is an arithmetic number, because the mean of its divisors is an integer number (8166200).

Almost surely, 2^823869640 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 823869640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1175932800).

823869640 is an abundant number, since it is smaller than the sum of its proper divisors (1527995960).

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

823869640 is a wasteful number, since it uses less digits than its factorization.

823869640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 85 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 46.

The square root of 823869640 is about 28703.1294461074. The cubic root of 823869640 is about 937.4601877019.

The spelling of 823869640 in words is "eight hundred twenty-three million, eight hundred sixty-nine thousand, six hundred forty".