309842 has 16 divisors (see below), whose sum is σ = 530712. Its totient is φ = 134400.

The previous prime is 309823. The next prime is 309851. The reversal of 309842 is 248903.

It can be written as a sum of positive squares in 4 ways, for example, as 292681 + 17161 = 541^2 + 131^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 309842.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92 + ... + 792.

2³⁰⁹⁸⁴² is an apocalyptic number.

309842 is a deficient number, since it is larger than the sum of its proper divisors (220870).

309842 is a wasteful number, since it uses less digits than its factorization.

309842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 733.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 309842 is about 556.6345300105. The cubic root of 309842 is about 67.6674944153.

The spelling of 309842 in words is "three hundred nine thousand, eight hundred forty-two".