309490343 has 4 divisors (see below), whose sum is σ = 309543480. Its totient is φ = 309437208.

The previous prime is 309490319. The next prime is 309490387. The reversal of 309490343 is 343094903.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 343094903 = 6607 ⋅51929.

It is a cyclic number.

It is not a de Polignac number, because 309490343 - 2¹⁶ = 309424807 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309490303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16580 + ... + 29897.

It is an arithmetic number, because the mean of its divisors is an integer number (77385870).

Almost surely, 2^309490343 is an apocalyptic number.

309490343 is the 9404-th centered heptagonal number.

309490343 is a deficient number, since it is larger than the sum of its proper divisors (53137).

309490343 is an equidigital number, since it uses as much as digits as its factorization.

309490343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53136.

The product of its (nonzero) digits is 34992, while the sum is 35.

The square root of 309490343 is about 17592.3376218171. The cubic root of 309490343 is about 676.4188485072.

The spelling of 309490343 in words is "three hundred nine million, four hundred ninety thousand, three hundred forty-three".