391914397 has 24 divisors (see below), whose sum is σ = 472612536. Its totient is φ = 323785728.

The previous prime is 391914377. The next prime is 391914401. The reversal of 391914397 is 793419193.

It can be written as a sum of positive squares in 4 ways, for example, as 91030681 + 300883716 = 9541^2 + 17346^2 .

It is not a de Polignac number, because 391914397 - 2⁷ = 391914269 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 (391914317) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 203913 + ... + 205825.

It is an arithmetic number, because the mean of its divisors is an integer number (19692189).

Almost surely, 2^391914397 is an apocalyptic number.

391914397 is a gapful number since it is divisible by the number (37) formed by its first and last digit.

It is an amenable number.

391914397 is a deficient number, since it is larger than the sum of its proper divisors (80698139).

391914397 is a wasteful number, since it uses less digits than its factorization.

391914397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2077 (or 2070 counting only the distinct ones).

The product of its digits is 183708, while the sum is 46.

The square root of 391914397 is about 19796.8279529828. The cubic root of 391914397 is about 731.8078647340.

The spelling of 391914397 in words is "three hundred ninety-one million, nine hundred fourteen thousand, three hundred ninety-seven".