391740249 has 4 divisors (see below), whose sum is σ = 522320336. Its totient is φ = 261160164.

The previous prime is 391740229. The next prime is 391740311. The reversal of 391740249 is 942047193.

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 not a de Polignac number, because 391740249 - 2¹¹ = 391738201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391740229) 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, 65290039 + ... + 65290044.

It is an arithmetic number, because the mean of its divisors is an integer number (130580084).

Almost surely, 2^391740249 is an apocalyptic number.

It is an amenable number.

391740249 is a deficient number, since it is larger than the sum of its proper divisors (130580087).

391740249 is a wasteful number, since it uses less digits than its factorization.

391740249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130580086.

The product of its (nonzero) digits is 54432, while the sum is 39.

The square root of 391740249 is about 19792.4290828589. The cubic root of 391740249 is about 731.6994552121.

The spelling of 391740249 in words is "three hundred ninety-one million, seven hundred forty thousand, two hundred forty-nine".