391780479 has 4 divisors (see below), whose sum is σ = 522373976. Its totient is φ = 261186984.

The previous prime is 391780463. The next prime is 391780483. The reversal of 391780479 is 974087193.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 391780479 - 2⁴ = 391780463 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 (391780409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65296744 + ... + 65296749.

It is an arithmetic number, because the mean of its divisors is an integer number (130593494).

Almost surely, 2^391780479 is an apocalyptic number.

391780479 is a deficient number, since it is larger than the sum of its proper divisors (130593497).

391780479 is a wasteful number, since it uses less digits than its factorization.

391780479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130593496.

The product of its (nonzero) digits is 381024, while the sum is 48.

The square root of 391780479 is about 19793.4453544601. The cubic root of 391780479 is about 731.7245017930.

The spelling of 391780479 in words is "three hundred ninety-one million, seven hundred eighty thousand, four hundred seventy-nine".