42013521 has 24 divisors (see below), whose sum is σ = 67013856. Its totient is φ = 25151040.

The previous prime is 42013501. The next prime is 42013523. The reversal of 42013521 is 12531024.

It is not a de Polignac number, because 42013521 - 2⁷ = 42013393 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 42013494 and 42013503.

It is not an unprimeable number, because it can be changed into a prime (42013523) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5661 + ... + 10773.

It is an arithmetic number, because the mean of its divisors is an integer number (2792244).

Almost surely, 2^42013521 is an apocalyptic number.

It is an amenable number.

42013521 is a deficient number, since it is larger than the sum of its proper divisors (25000335).

42013521 is a wasteful number, since it uses less digits than its factorization.

42013521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5213 (or 5210 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 42013521 is about 6481.7837822624. The cubic root of 42013521 is about 347.6399615630.

Adding to 42013521 its reverse (12531024), we get a palindrome (54544545).

The spelling of 42013521 in words is "forty-two million, thirteen thousand, five hundred twenty-one".