391239449 has 4 divisors (see below), whose sum is σ = 391396560. Its totient is φ = 391082340.

The previous prime is 391239427. The next prime is 391239463. The reversal of 391239449 is 944932193.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 391239449 - 2¹² = 391235353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391239049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74759 + ... + 79820.

It is an arithmetic number, because the mean of its divisors is an integer number (97849140).

Almost surely, 2^391239449 is an apocalyptic number.

It is an amenable number.

391239449 is a deficient number, since it is larger than the sum of its proper divisors (157111).

391239449 is a wasteful number, since it uses less digits than its factorization.

391239449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157110.

The product of its digits is 209952, while the sum is 44.

The square root of 391239449 is about 19779.7737348029. The cubic root of 391239449 is about 731.3875211784.

The spelling of 391239449 in words is "three hundred ninety-one million, two hundred thirty-nine thousand, four hundred forty-nine".