40003521 has 4 divisors (see below), whose sum is σ = 53338032. Its totient is φ = 26669012.

The previous prime is 40003519. The next prime is 40003541. The reversal of 40003521 is 12530004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40003521 - 2¹ = 40003519 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 40003521.

It is not an unprimeable number, because it can be changed into a prime (40003501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6667251 + ... + 6667256.

It is an arithmetic number, because the mean of its divisors is an integer number (13334508).

Almost surely, 2^40003521 is an apocalyptic number.

It is an amenable number.

40003521 is a deficient number, since it is larger than the sum of its proper divisors (13334511).

40003521 is a wasteful number, since it uses less digits than its factorization.

40003521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13334510.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 40003521 is about 6324.8336737024. The cubic root of 40003521 is about 342.0052237498.

Adding to 40003521 its reverse (12530004), we get a palindrome (52533525).

The spelling of 40003521 in words is "forty million, three thousand, five hundred twenty-one".