731438640 has 160 divisors (see below), whose sum is σ = 2629117440. Its totient is φ = 186557184.

The previous prime is 731438639. The next prime is 731438699. The reversal of 731438640 is 46834137.

731438640 is a `hidden beast` number, since 7 + 3 + 1 + 4 + 3 + 8 + 640 = 666.

731438640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 = 731438595 and 731438604.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42319 + ... + 57041.

It is an arithmetic number, because the mean of its divisors is an integer number (16431984).

Almost surely, 2^731438640 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 731438640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1314558720).

731438640 is an abundant number, since it is smaller than the sum of its proper divisors (1897678800).

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

731438640 is a wasteful number, since it uses less digits than its factorization.

731438640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14768 (or 14756 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 731438640 is about 27045.1222958965. The cubic root of 731438640 is about 901.0024386042.

It can be divided in two parts, 7314 and 38640, that added together give a palindrome (45954).

The spelling of 731438640 in words is "seven hundred thirty-one million, four hundred thirty-eight thousand, six hundred forty".