391299121 has 8 divisors (see below), whose sum is σ = 401108904. Its totient is φ = 381502080.

The previous prime is 391299119. The next prime is 391299127. The reversal of 391299121 is 121992193.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 75881521 + 315417600 = 8711^2 + 17760^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 391299121 - 2¹ = 391299119 is a prime.

It is not an unprimeable number, because it can be changed into a prime (391299127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99631 + ... + 103483.

It is an arithmetic number, because the mean of its divisors is an integer number (50138613).

Almost surely, 2^391299121 is an apocalyptic number.

It is an amenable number.

391299121 is a deficient number, since it is larger than the sum of its proper divisors (9809783).

391299121 is a wasteful number, since it uses less digits than its factorization.

391299121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6371.

The product of its digits is 8748, while the sum is 37.

The square root of 391299121 is about 19781.2820868618. The cubic root of 391299121 is about 731.4247031289.

The spelling of 391299121 in words is "three hundred ninety-one million, two hundred ninety-nine thousand, one hundred twenty-one".