309988445 has 8 divisors (see below), whose sum is σ = 400600536. Its totient is φ = 228914496.

The previous prime is 309988423. The next prime is 309988447. The reversal of 309988445 is 544889903.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5067001 + 304921444 = 2251^2 + 17462^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 309988445 - 2⁶ = 309988381 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 309988393 and 309988402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309988447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2384462 + ... + 2384591.

It is an arithmetic number, because the mean of its divisors is an integer number (50075067).

Almost surely, 2^309988445 is an apocalyptic number.

It is an amenable number.

309988445 is a deficient number, since it is larger than the sum of its proper divisors (90612091).

309988445 is a wasteful number, since it uses less digits than its factorization.

309988445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4769071.

The product of its (nonzero) digits is 1244160, while the sum is 50.

The square root of 309988445 is about 17606.4887186514. The cubic root of 309988445 is about 676.7815361731.

The spelling of 309988445 in words is "three hundred nine million, nine hundred eighty-eight thousand, four hundred forty-five".