391011041221 has 2 divisors, whose sum is σ = 391011041222. Its totient is φ = 391011041220.

The previous prime is 391011041191. The next prime is 391011041233. The reversal of 391011041221 is 122140110193.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 205671320100 + 185339721121 = 453510^2 + 430511^2 .

It is a cyclic number.

It is not a de Polignac number, because 391011041221 - 2³⁵ = 356651302853 is a prime.

It is a super-2 number, since 2×391011041221² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391011041261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195505520610 + 195505520611.

It is an arithmetic number, because the mean of its divisors is an integer number (195505520611).

Almost surely, 2^391011041221 is an apocalyptic number.

It is an amenable number.

391011041221 is a deficient number, since it is larger than the sum of its proper divisors (1).

391011041221 is an equidigital number, since it uses as much as digits as its factorization.

391011041221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The spelling of 391011041221 in words is "three hundred ninety-one billion, eleven million, forty-one thousand, two hundred twenty-one".