391640949 has 48 divisors (see below), whose sum is σ = 673054720. Its totient is φ = 214734240.

The previous prime is 391640891. The next prime is 391640959. The reversal of 391640949 is 949046193.

It is not a de Polignac number, because 391640949 - 2²³ = 383252341 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391640959) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 247242 + ... + 248820.

Almost surely, 2^391640949 is an apocalyptic number.

It is an amenable number.

391640949 is a deficient number, since it is larger than the sum of its proper divisors (281413771).

391640949 is a wasteful number, since it uses less digits than its factorization.

391640949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1750 (or 1747 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The square root of 391640949 is about 19789.9203889253. The cubic root of 391640949 is about 731.6376252145.

The spelling of 391640949 in words is "three hundred ninety-one million, six hundred forty thousand, nine hundred forty-nine".