318321640 has 216 divisors, whose sum is σ = 932218470. Its totient is φ = 97493760.

The previous prime is 318321629. The next prime is 318321643. The reversal of 318321640 is 46123813.

It can be written as a sum of positive squares in 3 ways, for example, as 137311524 + 181010116 = 11718^2 + 13454^2 .

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 318321599 and 318321608.

It is not an unprimeable number, because it can be changed into a prime (318321643) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 10268425 + ... + 10268455.

Almost surely, 2^318321640 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 318321640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (466109235).

318321640 is an abundant number, since it is smaller than the sum of its proper divisors (613896830).

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

318321640 is a wasteful number, since it uses less digits than its factorization.

318321640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 318321640 is about 17841.5705586700. The cubic root of 318321640 is about 682.7924672456.

The spelling of 318321640 in words is "three hundred eighteen million, three hundred twenty-one thousand, six hundred forty".