509942 has 4 divisors (see below), whose sum is σ = 764916. Its totient is φ = 254970.

The previous prime is 509939. The next prime is 509947. The reversal of 509942 is 249905.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (509947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127484 + ... + 127487.

It is an arithmetic number, because the mean of its divisors is an integer number (191229).

2⁵⁰⁹⁹⁴² is an apocalyptic number.

509942 is a deficient number, since it is larger than the sum of its proper divisors (254974).

509942 is a wasteful number, since it uses less digits than its factorization.

509942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254973.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 509942 is about 714.1022335772. The cubic root of 509942 is about 79.8926685639.

The spelling of 509942 in words is "five hundred nine thousand, nine hundred forty-two".