42521440 has 48 divisors (see below), whose sum is σ = 108189648. Its totient is φ = 15699456.

The previous prime is 42521419. The next prime is 42521443. The reversal of 42521440 is 4412524.

It is a happy number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42521443) 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, 8142 + ... + 12301.

It is an arithmetic number, because the mean of its divisors is an integer number (2253951).

Almost surely, 2^42521440 is an apocalyptic number.

42521440 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

42521440 is an abundant number, since it is smaller than the sum of its proper divisors (65668208).

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

42521440 is a wasteful number, since it uses less digits than its factorization.

42521440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20471 (or 20463 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 22.

The square root of 42521440 is about 6520.8465708066. The cubic root of 42521440 is about 349.0352752909.

Adding to 42521440 its reverse (4412524), we get a palindrome (46933964).

The spelling of 42521440 in words is "forty-two million, five hundred twenty-one thousand, four hundred forty".