391993345 has 16 divisors (see below), whose sum is σ = 479905920. Its totient is φ = 307286784.

The previous prime is 391993337. The next prime is 391993363. The reversal of 391993345 is 543399193.

It is a cyclic number.

It is not a de Polignac number, because 391993345 - 2³ = 391993337 is a prime.

It is a super-4 number, since 4×391993345⁴ (a number of 35 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 391993295 and 391993304.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97444 + ... + 101386.

It is an arithmetic number, because the mean of its divisors is an integer number (29994120).

Almost surely, 2^391993345 is an apocalyptic number.

It is an amenable number.

391993345 is a deficient number, since it is larger than the sum of its proper divisors (87912575).

391993345 is a wasteful number, since it uses less digits than its factorization.

391993345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4344.

The product of its digits is 393660, while the sum is 46.

The square root of 391993345 is about 19798.8218083804. The cubic root of 391993345 is about 731.8570003690.

The spelling of 391993345 in words is "three hundred ninety-one million, nine hundred ninety-three thousand, three hundred forty-five".