42390065 has 4 divisors (see below), whose sum is σ = 50868084. Its totient is φ = 33912048.

The previous prime is 42390043. The next prime is 42390071. The reversal of 42390065 is 56009324.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5216656 + 37173409 = 2284^2 + 6097^2 .

It is a cyclic number.

It is not a de Polignac number, because 42390065 - 2⁶ = 42390001 is a prime.

It is a super-2 number, since 2×42390065² = 3593835221408450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4239002 + ... + 4239011.

It is an arithmetic number, because the mean of its divisors is an integer number (12717021).

Almost surely, 2^42390065 is an apocalyptic number.

It is an amenable number.

42390065 is a deficient number, since it is larger than the sum of its proper divisors (8478019).

42390065 is an equidigital number, since it uses as much as digits as its factorization.

42390065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8478018.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 42390065 is about 6510.7653159978. The cubic root of 42390065 is about 348.6754425820.

Adding to 42390065 its reverse (56009324), we get a palindrome (98399389).

The spelling of 42390065 in words is "forty-two million, three hundred ninety thousand, sixty-five".