320121391 has 2 divisors, whose sum is σ = 320121392. Its totient is φ = 320121390.

The previous prime is 320121353. The next prime is 320121413. The reversal of 320121391 is 193121023.

It is an a-pointer prime, because the next prime (320121413) can be obtained adding 320121391 to its sum of digits (22).

It is a strong prime.

It is an emirp because it is prime and its reverse (193121023) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 320121391 - 2¹¹ = 320119343 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (320121091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160060695 + 160060696.

It is an arithmetic number, because the mean of its divisors is an integer number (160060696).

Almost surely, 2^320121391 is an apocalyptic number.

320121391 is a deficient number, since it is larger than the sum of its proper divisors (1).

320121391 is an equidigital number, since it uses as much as digits as its factorization.

320121391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 320121391 is about 17891.9364798783. The cubic root of 320121391 is about 684.0768576073.

The spelling of 320121391 in words is "three hundred twenty million, one hundred twenty-one thousand, three hundred ninety-one".