42009813 has 8 divisors (see below), whose sum is σ = 62236800. Its totient is φ = 28006524.

The previous prime is 42009809. The next prime is 42009823. The reversal of 42009813 is 31890024.

It is not a de Polignac number, because 42009813 - 2² = 42009809 is a prime.

It is a super-3 number, since 3×42009813³ (a number of 24 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 1555919 = 42009813 / (4 + 2 + 0 + 0 + 9 + 8 + 1 + 3).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42009823) 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, 777933 + ... + 777986.

It is an arithmetic number, because the mean of its divisors is an integer number (7779600).

Almost surely, 2^42009813 is an apocalyptic number.

It is an amenable number.

42009813 is a deficient number, since it is larger than the sum of its proper divisors (20226987).

42009813 is a wasteful number, since it uses less digits than its factorization.

42009813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1555928 (or 1555922 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 42009813 is about 6481.4977435775. The cubic root of 42009813 is about 347.6297340071.

Adding to 42009813 its reverse (31890024), we get a palindrome (73899837).

The spelling of 42009813 in words is "forty-two million, nine thousand, eight hundred thirteen".