391123879 has 16 divisors (see below), whose sum is σ = 419420160. Its totient is φ = 363450240.

The previous prime is 391123867. The next prime is 391123883. The reversal of 391123879 is 978321193.

It is a cyclic number.

It is not a de Polignac number, because 391123879 - 2⁵ = 391123847 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 (391123079) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 528892 + ... + 529630.

It is an arithmetic number, because the mean of its divisors is an integer number (26213760).

Almost surely, 2^391123879 is an apocalyptic number.

391123879 is a deficient number, since it is larger than the sum of its proper divisors (28296281).

391123879 is a wasteful number, since it uses less digits than its factorization.

391123879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1110.

The product of its digits is 81648, while the sum is 43.

The square root of 391123879 is about 19776.8521003723. The cubic root of 391123879 is about 731.3154981242.

The spelling of 391123879 in words is "three hundred ninety-one million, one hundred twenty-three thousand, eight hundred seventy-nine".