391380917 has 4 divisors (see below), whose sum is σ = 391425036. Its totient is φ = 391336800.

The previous prime is 391380907. The next prime is 391380937. The reversal of 391380917 is 719083193.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 255168676 + 136212241 = 15974^2 + 11671^2 .

It is a cyclic number.

It is not a de Polignac number, because 391380917 - 2¹⁰ = 391379893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391380907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3608 + ... + 28209.

It is an arithmetic number, because the mean of its divisors is an integer number (97856259).

Almost surely, 2^391380917 is an apocalyptic number.

It is an amenable number.

391380917 is a deficient number, since it is larger than the sum of its proper divisors (44119).

391380917 is a wasteful number, since it uses less digits than its factorization.

391380917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44118.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 391380917 is about 19783.3494889010. The cubic root of 391380917 is about 731.4756645235.

The spelling of 391380917 in words is "three hundred ninety-one million, three hundred eighty thousand, nine hundred seventeen".