391123321221 has 8 divisors (see below), whose sum is σ = 548945012320. Its totient is φ = 247025255472.

The previous prime is 391123321163. The next prime is 391123321223. The reversal of 391123321221 is 122123321193.

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

It is not a de Polignac number, because 391123321221 - 2¹³ = 391123313029 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 (391123321223) 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, 3430906270 + ... + 3430906383.

It is an arithmetic number, because the mean of its divisors is an integer number (68618126540).

Almost surely, 2^391123321221 is an apocalyptic number.

It is an amenable number.

391123321221 is a deficient number, since it is larger than the sum of its proper divisors (157821691099).

391123321221 is a wasteful number, since it uses less digits than its factorization.

391123321221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6861812675.

The product of its digits is 3888, while the sum is 30.

The spelling of 391123321221 in words is "three hundred ninety-one billion, one hundred twenty-three million, three hundred twenty-one thousand, two hundred twenty-one".