823638868 has 24 divisors (see below), whose sum is σ = 1581535368. Its totient is φ = 372967296.

The previous prime is 823638863. The next prime is 823638913. The reversal of 823638868 is 868836328.

It can be written as a sum of positive squares in 4 ways, for example, as 207705744 + 615933124 = 14412^2 + 24818^2 .

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (823638863) 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, 146671 + ... + 152182.

It is an arithmetic number, because the mean of its divisors is an integer number (65897307).

Almost surely, 2^823638868 is an apocalyptic number.

It is an amenable number.

823638868 is a deficient number, since it is larger than the sum of its proper divisors (757896500).

823638868 is a wasteful number, since it uses less digits than its factorization.

823638868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298923 (or 298921 counting only the distinct ones).

The product of its digits is 2654208, while the sum is 52.

The square root of 823638868 is about 28699.1091847813. The cubic root of 823638868 is about 937.3726496763.

The spelling of 823638868 in words is "eight hundred twenty-three million, six hundred thirty-eight thousand, eight hundred sixty-eight".