391709672 has 16 divisors (see below), whose sum is σ = 734922240. Its totient is φ = 195730416.

The previous prime is 391709653. The next prime is 391709677. The reversal of 391709672 is 276907193.

It is a happy number.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (391709677) 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, 1418 + ... + 28025.

It is an arithmetic number, because the mean of its divisors is an integer number (45932640).

Almost surely, 2^391709672 is an apocalyptic number.

It is an amenable number.

391709672 is a deficient number, since it is larger than the sum of its proper divisors (343212568).

391709672 is a wasteful number, since it uses less digits than its factorization.

391709672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31112 (or 31108 counting only the distinct ones).

The product of its (nonzero) digits is 142884, while the sum is 44.

The square root of 391709672 is about 19791.6566259624. The cubic root of 391709672 is about 731.6804172939.

The spelling of 391709672 in words is "three hundred ninety-one million, seven hundred nine thousand, six hundred seventy-two".