309531029 has 2 divisors, whose sum is σ = 309531030. Its totient is φ = 309531028.

The previous prime is 309530999. The next prime is 309531031. The reversal of 309531029 is 920135903.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 269714929 + 39816100 = 16423^2 + 6310^2 .

It is an emirp because it is prime and its reverse (920135903) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 309531029 - 2¹² = 309526933 is a prime.

Together with 309531031, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 309530986 and 309531004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (309531059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154765514 + 154765515.

It is an arithmetic number, because the mean of its divisors is an integer number (154765515).

Almost surely, 2^309531029 is an apocalyptic number.

It is an amenable number.

309531029 is a deficient number, since it is larger than the sum of its proper divisors (1).

309531029 is an equidigital number, since it uses as much as digits as its factorization.

309531029 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7290, while the sum is 32.

The square root of 309531029 is about 17593.4939395221. The cubic root of 309531029 is about 676.4484881734.

The spelling of 309531029 in words is "three hundred nine million, five hundred thirty-one thousand, twenty-nine".