391948397 has 16 divisors (see below), whose sum is σ = 432505920. Its totient is φ = 353808000.

The previous prime is 391948373. The next prime is 391948423. The reversal of 391948397 is 793849193.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 391948397 - 2¹⁰ = 391947373 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 (391948357) 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, 27647 + ... + 39347.

It is an arithmetic number, because the mean of its divisors is an integer number (27031620).

Almost surely, 2^391948397 is an apocalyptic number.

It is an amenable number.

391948397 is a deficient number, since it is larger than the sum of its proper divisors (40557523).

391948397 is a wasteful number, since it uses less digits than its factorization.

391948397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11804.

The product of its digits is 1469664, while the sum is 53.

The square root of 391948397 is about 19797.6866577891. The cubic root of 391948397 is about 731.8290264537.

The spelling of 391948397 in words is "three hundred ninety-one million, nine hundred forty-eight thousand, three hundred ninety-seven".