42440405 has 16 divisors (see below), whose sum is σ = 60735744. Its totient is φ = 27836160.

The previous prime is 42440401. The next prime is 42440423. The reversal of 42440405 is 50404424.

It is not a de Polignac number, because 42440405 - 2² = 42440401 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42440401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25556 + ... + 27165.

It is an arithmetic number, because the mean of its divisors is an integer number (3795984).

Almost surely, 2^42440405 is an apocalyptic number.

It is an amenable number.

42440405 is a deficient number, since it is larger than the sum of its proper divisors (18295339).

42440405 is a wasteful number, since it uses less digits than its factorization.

42440405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52756.

The product of its (nonzero) digits is 2560, while the sum is 23.

The square root of 42440405 is about 6514.6300739182. The cubic root of 42440405 is about 348.8134102742.

Adding to 42440405 its reverse (50404424), we get a palindrome (92844829).

The spelling of 42440405 in words is "forty-two million, four hundred forty thousand, four hundred five".