42405140 has 24 divisors (see below), whose sum is σ = 94289832. Its totient is φ = 15964160.

The previous prime is 42405137. The next prime is 42405149. The reversal of 42405140 is 4150424.

It can be written as a sum of positive squares in 4 ways, for example, as 595984 + 41809156 = 772^2 + 6466^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42405149) 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, 62021 + ... + 62700.

It is an arithmetic number, because the mean of its divisors is an integer number (3928743).

Almost surely, 2^42405140 is an apocalyptic number.

It is an amenable number.

42405140 is an abundant number, since it is smaller than the sum of its proper divisors (51884692).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

42405140 is a wasteful number, since it uses less digits than its factorization.

42405140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124747 (or 124745 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 42405140 is about 6511.9229110916. The cubic root of 42405140 is about 348.7167703423.

Adding to 42405140 its reverse (4150424), we get a palindrome (46555564).

The spelling of 42405140 in words is "forty-two million, four hundred five thousand, one hundred forty".