391897967 has 8 divisors (see below), whose sum is σ = 415301040. Its totient is φ = 369154240.

The previous prime is 391897963. The next prime is 391897973. The reversal of 391897967 is 769798193.

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 391897967 - 2² = 391897963 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 (391897963) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 163613 + ... + 165990.

It is an arithmetic number, because the mean of its divisors is an integer number (51912630).

Almost surely, 2^391897967 is an apocalyptic number.

391897967 is a deficient number, since it is larger than the sum of its proper divisors (23403073).

391897967 is a wasteful number, since it uses less digits than its factorization.

391897967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329673.

The product of its digits is 5143824, while the sum is 59.

The square root of 391897967 is about 19796.4129831644. The cubic root of 391897967 is about 731.7976382055.

The spelling of 391897967 in words is "three hundred ninety-one million, eight hundred ninety-seven thousand, nine hundred sixty-seven".