309123481 has 2 divisors, whose sum is σ = 309123482. Its totient is φ = 309123480.

The previous prime is 309123443. The next prime is 309123533. The reversal of 309123481 is 184321903.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 309056400 + 67081 = 17580^2 + 259^2 .

It is an emirp because it is prime and its reverse (184321903) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 309123481 - 2⁹ = 309122969 is a prime.

It is a super-2 number, since 2×309123481² = 191114653011114722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (309123181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154561740 + 154561741.

It is an arithmetic number, because the mean of its divisors is an integer number (154561741).

Almost surely, 2^309123481 is an apocalyptic number.

It is an amenable number.

309123481 is a deficient number, since it is larger than the sum of its proper divisors (1).

309123481 is an equidigital number, since it uses as much as digits as its factorization.

309123481 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 309123481 is about 17581.9077747553. The cubic root of 309123481 is about 676.1514729191.

The spelling of 309123481 in words is "three hundred nine million, one hundred twenty-three thousand, four hundred eighty-one".