391313745 has 24 divisors (see below), whose sum is σ = 680747496. Its totient is φ = 207940608.

The previous prime is 391313711. The next prime is 391313749. The reversal of 391313745 is 547313193.

It can be written as a sum of positive squares in 4 ways, for example, as 86881041 + 304432704 = 9321^2 + 17448^2 .

It is not a de Polignac number, because 391313745 - 2¹⁸ = 391051601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (391313749) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3232 + ... + 28161.

It is an arithmetic number, because the mean of its divisors is an integer number (28364479).

Almost surely, 2^391313745 is an apocalyptic number.

It is an amenable number.

391313745 is a deficient number, since it is larger than the sum of its proper divisors (289433751).

391313745 is a wasteful number, since it uses less digits than its factorization.

391313745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31681 (or 31678 counting only the distinct ones).

The product of its digits is 34020, while the sum is 36.

The square root of 391313745 is about 19781.6517257786. The cubic root of 391313745 is about 731.4338148468.

The spelling of 391313745 in words is "three hundred ninety-one million, three hundred thirteen thousand, seven hundred forty-five".