42640344 has 80 divisors (see below), whose sum is σ = 124668720. Its totient is φ = 13590720.

The previous prime is 42640343. The next prime is 42640363. The reversal of 42640344 is 44304624.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42640343) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13474 + ... + 16334.

It is an arithmetic number, because the mean of its divisors is an integer number (1558359).

Almost surely, 2^42640344 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42640344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62334360).

42640344 is an abundant number, since it is smaller than the sum of its proper divisors (82028376).

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

42640344 is a wasteful number, since it uses less digits than its factorization.

42640344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2902 (or 2889 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

The square root of 42640344 is about 6529.9574271200. The cubic root of 42640344 is about 349.3603118388.

Adding to 42640344 its reverse (44304624), we get a palindrome (86944968).

The spelling of 42640344 in words is "forty-two million, six hundred forty thousand, three hundred forty-four".