391479989 has 8 divisors (see below), whose sum is σ = 393467808. Its totient is φ = 389497680.

The previous prime is 391479983. The next prime is 391480021. The reversal of 391479989 is 989974193.

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 391479989 - 2⁴ = 391479973 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 (391479983) 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, 223214 + ... + 224960.

It is an arithmetic number, because the mean of its divisors is an integer number (49183476).

Almost surely, 2^391479989 is an apocalyptic number.

It is an amenable number.

391479989 is a deficient number, since it is larger than the sum of its proper divisors (1987819).

391479989 is a wasteful number, since it uses less digits than its factorization.

391479989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2755.

The product of its digits is 4408992, while the sum is 59.

The square root of 391479989 is about 19785.8532542825. The cubic root of 391479989 is about 731.5373798840.

The spelling of 391479989 in words is "three hundred ninety-one million, four hundred seventy-nine thousand, nine hundred eighty-nine".