309312845 has 4 divisors (see below), whose sum is σ = 371175420. Its totient is φ = 247450272.

The previous prime is 309312821. The next prime is 309312851. The reversal of 309312845 is 548213903.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 548213903 = 7411 ⋅73973.

It can be written as a sum of positive squares in 2 ways, for example, as 151634596 + 157678249 = 12314^2 + 12557^2 .

It is a cyclic number.

It is not a de Polignac number, because 309312845 - 2²⁰ = 308264269 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30931280 + ... + 30931289.

It is an arithmetic number, because the mean of its divisors is an integer number (92793855).

Almost surely, 2^309312845 is an apocalyptic number.

It is an amenable number.

309312845 is a deficient number, since it is larger than the sum of its proper divisors (61862575).

309312845 is an equidigital number, since it uses as much as digits as its factorization.

309312845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61862574.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 309312845 is about 17587.2921451826. The cubic root of 309312845 is about 676.2895111891.

The spelling of 309312845 in words is "three hundred nine million, three hundred twelve thousand, eight hundred forty-five".