309356989 has 2 divisors, whose sum is σ = 309356990. Its totient is φ = 309356988.

The previous prime is 309356977. The next prime is 309357053. The reversal of 309356989 is 989653903.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 287031364 + 22325625 = 16942^2 + 4725^2 .

It is a cyclic number.

It is not a de Polignac number, because 309356989 - 2⁹ = 309356477 is a prime.

It is a super-2 number, since 2×309356989² = 191403493286292242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (309356909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154678494 + 154678495.

It is an arithmetic number, because the mean of its divisors is an integer number (154678495).

Almost surely, 2^309356989 is an apocalyptic number.

It is an amenable number.

309356989 is a deficient number, since it is larger than the sum of its proper divisors (1).

309356989 is an equidigital number, since it uses as much as digits as its factorization.

309356989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1574640, while the sum is 52.

The square root of 309356989 is about 17588.5470974723. The cubic root of 309356989 is about 676.3216821820.

The spelling of 309356989 in words is "three hundred nine million, three hundred fifty-six thousand, nine hundred eighty-nine".