320238728 has 8 divisors (see below), whose sum is σ = 600447630. Its totient is φ = 160119360.

The previous prime is 320238727. The next prime is 320238731. The reversal of 320238728 is 827832023.

It can be written as a sum of positive squares in only one way, i.e., 268369924 + 51868804 = 16382^2 + 7202^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×320238728² = 205105685822115968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (320238727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20014913 + ... + 20014928.

Almost surely, 2^320238728 is an apocalyptic number.

It is an amenable number.

320238728 is a deficient number, since it is larger than the sum of its proper divisors (280208902).

320238728 is a wasteful number, since it uses less digits than its factorization.

320238728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40029847 (or 40029843 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 35.

The square root of 320238728 is about 17895.2152264230. The cubic root of 320238728 is about 684.1604276982.

The spelling of 320238728 in words is "three hundred twenty million, two hundred thirty-eight thousand, seven hundred twenty-eight".