42999809 has 8 divisors (see below), whose sum is σ = 44620968. Its totient is φ = 41402880.

The previous prime is 42999797. The next prime is 42999823. The reversal of 42999809 is 90899924.

It can be written as a sum of positive squares in 4 ways, for example, as 26214400 + 16785409 = 5120^2 + 4097^2 .

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 42999809 - 2⁸ = 42999553 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42999829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2402 + ... + 9579.

It is an arithmetic number, because the mean of its divisors is an integer number (5577621).

It is a Proth number, since it is equal to 5249 ⋅ 2¹³ + 1 and 5249 < 2¹³.

Almost surely, 2^42999809 is an apocalyptic number.

It is an amenable number.

42999809 is a deficient number, since it is larger than the sum of its proper divisors (1621159).

42999809 is a wasteful number, since it uses less digits than its factorization.

42999809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12115.

The product of its (nonzero) digits is 419904, while the sum is 50.

The square root of 42999809 is about 6557.4239606724. The cubic root of 42999809 is about 350.3392873177.

The spelling of 42999809 in words is "forty-two million, nine hundred ninety-nine thousand, eight hundred nine".