391022121 has 8 divisors (see below), whose sum is σ = 595843264. Its totient is φ = 223441200.

The previous prime is 391022119. The next prime is 391022141. The reversal of 391022121 is 121220193.

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

It is not a de Polignac number, because 391022121 - 2¹ = 391022119 is a prime.

It is a super-2 number, since 2×391022121² = 305796598222677282, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 18620101 = 391022121 / (3 + 9 + 1 + 0 + 2 + 2 + 1 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (391022141) 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, 9310030 + ... + 9310071.

It is an arithmetic number, because the mean of its divisors is an integer number (74480408).

Almost surely, 2^391022121 is an apocalyptic number.

It is an amenable number.

391022121 is a deficient number, since it is larger than the sum of its proper divisors (204821143).

391022121 is a wasteful number, since it uses less digits than its factorization.

391022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18620111.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 391022121 is about 19774.2792789017. The cubic root of 391022121 is about 731.2520709416.

The spelling of 391022121 in words is "three hundred ninety-one million, twenty-two thousand, one hundred twenty-one".