42640444 has 48 divisors (see below), whose sum is σ = 93703680. Its totient is φ = 16493760.

The previous prime is 42640441. The next prime is 42640489. The reversal of 42640444 is 44404624.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42640441) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 51022 + ... + 51850.

It is an arithmetic number, because the mean of its divisors is an integer number (1952160).

Almost surely, 2^42640444 is an apocalyptic number.

42640444 is a gapful number since it is divisible by the number (44) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42640444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46851840).

42640444 is an abundant number, since it is smaller than the sum of its proper divisors (51063236).

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

42640444 is a wasteful number, since it uses less digits than its factorization.

42640444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1018 (or 1016 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 28.

The square root of 42640444 is about 6529.9650841333. The cubic root of 42640444 is about 349.3605849449.

The spelling of 42640444 in words is "forty-two million, six hundred forty thousand, four hundred forty-four".