391654121 has 4 divisors (see below), whose sum is σ = 391792212. Its totient is φ = 391516032.

The previous prime is 391654117. The next prime is 391654141. The reversal of 391654121 is 121456193.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 168480400 + 223173721 = 12980^2 + 14939^2 .

It is a cyclic number.

It is not a de Polignac number, because 391654121 - 2² = 391654117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (391654141) 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, 64700 + ... + 70493.

It is an arithmetic number, because the mean of its divisors is an integer number (97948053).

Almost surely, 2^391654121 is an apocalyptic number.

It is an amenable number.

391654121 is a deficient number, since it is larger than the sum of its proper divisors (138091).

391654121 is a wasteful number, since it uses less digits than its factorization.

391654121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138090.

The product of its digits is 6480, while the sum is 32.

The square root of 391654121 is about 19790.2531818064. The cubic root of 391654121 is about 731.6458274746.

The spelling of 391654121 in words is "three hundred ninety-one million, six hundred fifty-four thousand, one hundred twenty-one".