391049971 has 8 divisors (see below), whose sum is σ = 425473664. Its totient is φ = 357246720.

The previous prime is 391049969. The next prime is 391049999. The reversal of 391049971 is 179940193.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 391049971 - 2¹ = 391049969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391049471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 153795 + ... + 156316.

It is an arithmetic number, because the mean of its divisors is an integer number (53184208).

Almost surely, 2^391049971 is an apocalyptic number.

391049971 is a deficient number, since it is larger than the sum of its proper divisors (34423693).

391049971 is a wasteful number, since it uses less digits than its factorization.

391049971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310221.

The product of its (nonzero) digits is 61236, while the sum is 43.

The square root of 391049971 is about 19774.9834639627. The cubic root of 391049971 is about 731.2694313292.

The spelling of 391049971 in words is "three hundred ninety-one million, forty-nine thousand, nine hundred seventy-one".