391231291 has 8 divisors (see below), whose sum is σ = 433168704. Its totient is φ = 350355720.

The previous prime is 391231271. The next prime is 391231331. The reversal of 391231291 is 192132193.

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

It is not a de Polignac number, because 391231291 - 2⁵ = 391231259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391231201) 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, 264685 + ... + 266158.

It is an arithmetic number, because the mean of its divisors is an integer number (54146088).

Almost surely, 2^391231291 is an apocalyptic number.

391231291 is a deficient number, since it is larger than the sum of its proper divisors (41937413).

391231291 is a wasteful number, since it uses less digits than its factorization.

391231291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530921.

The product of its digits is 2916, while the sum is 31.

The square root of 391231291 is about 19779.5675129665. The cubic root of 391231291 is about 731.3824375900.

The spelling of 391231291 in words is "three hundred ninety-one million, two hundred thirty-one thousand, two hundred ninety-one".