309739405 has 16 divisors (see below), whose sum is σ = 394072560. Its totient is φ = 232906752.

The previous prime is 309739369. The next prime is 309739421. The reversal of 309739405 is 504937903.

It can be written as a sum of positive squares in 8 ways, for example, as 2157961 + 307581444 = 1469^2 + 17538^2 .

It is a 7-Lehmer number, since φ(309739405) divides (309739405-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 309739405 - 2¹⁷ = 309608333 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77701 + ... + 81589.

It is an arithmetic number, because the mean of its divisors is an integer number (24629535).

Almost surely, 2^309739405 is an apocalyptic number.

It is an amenable number.

309739405 is a deficient number, since it is larger than the sum of its proper divisors (84333155).

309739405 is a wasteful number, since it uses less digits than its factorization.

309739405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4848.

The product of its (nonzero) digits is 102060, while the sum is 40.

The square root of 309739405 is about 17599.4149050473. The cubic root of 309739405 is about 676.6002489538.

The spelling of 309739405 in words is "three hundred nine million, seven hundred thirty-nine thousand, four hundred five".