323729640 has 288 divisors, whose sum is σ = 1210149720. Its totient is φ = 74760192.

The previous prime is 323729633. The next prime is 323729647. The reversal of 323729640 is 46927323.

It is a happy number.

323729640 is a `hidden beast` number, since 3 + 2 + 3 + 7 + 2 + 9 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (323729633) and next prime (323729647).

It can be written as a sum of positive squares in 12 ways, for example, as 23677956 + 300051684 = 4866^2 + 17322^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 323729595 and 323729604.

It is not an unprimeable number, because it can be changed into a prime (323729647) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1034124 + ... + 1034436.

Almost surely, 2^323729640 is an apocalyptic number.

323729640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 323729640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (605074860).

323729640 is an abundant number, since it is smaller than the sum of its proper divisors (886420080).

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

323729640 is a wasteful number, since it uses less digits than its factorization.

323729640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 36.

The square root of 323729640 is about 17992.4884326766. The cubic root of 323729640 is about 686.6374522819.

The spelling of 323729640 in words is "three hundred twenty-three million, seven hundred twenty-nine thousand, six hundred forty".