391345028 has 6 divisors (see below), whose sum is σ = 684853806. Its totient is φ = 195672512.

The previous prime is 391345027. The next prime is 391345037. The reversal of 391345028 is 820543193.

It can be written as a sum of positive squares in only one way, i.e., 206439424 + 184905604 = 14368^2 + 13598^2 .

It is not an unprimeable number, because it can be changed into a prime (391345027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48918125 + ... + 48918132.

It is an arithmetic number, because the mean of its divisors is an integer number (114142301).

Almost surely, 2^391345028 is an apocalyptic number.

It is an amenable number.

391345028 is a deficient number, since it is larger than the sum of its proper divisors (293508778).

391345028 is a wasteful number, since it uses less digits than its factorization.

391345028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97836261 (or 97836259 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 391345028 is about 19782.4424174570. The cubic root of 391345028 is about 731.4533054598.

The spelling of 391345028 in words is "three hundred ninety-one million, three hundred forty-five thousand, twenty-eight".