391041647 has 4 divisors (see below), whose sum is σ = 391897776. Its totient is φ = 390185520.

The previous prime is 391041617. The next prime is 391041661. The reversal of 391041647 is 746140193.

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

It is a cyclic number.

It is not a de Polignac number, because 391041647 - 2¹⁶ = 390976111 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 (391041617) 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, 427379 + ... + 428292.

It is an arithmetic number, because the mean of its divisors is an integer number (97974444).

Almost surely, 2^391041647 is an apocalyptic number.

391041647 is a deficient number, since it is larger than the sum of its proper divisors (856129).

391041647 is an equidigital number, since it uses as much as digits as its factorization.

391041647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856128.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 391041647 is about 19774.7729949044. The cubic root of 391041647 is about 731.2642426232.

The spelling of 391041647 in words is "three hundred ninety-one million, forty-one thousand, six hundred forty-seven".