40065521 has 4 divisors (see below), whose sum is σ = 40084032. Its totient is φ = 40047012.

The previous prime is 40065503. The next prime is 40065541. The reversal of 40065521 is 12556004.

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 40065521 - 2¹⁸ = 39803377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40065541) 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, 5501 + ... + 10506.

It is an arithmetic number, because the mean of its divisors is an integer number (10021008).

Almost surely, 2^40065521 is an apocalyptic number.

It is an amenable number.

40065521 is a deficient number, since it is larger than the sum of its proper divisors (18511).

40065521 is a wasteful number, since it uses less digits than its factorization.

40065521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18510.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 40065521 is about 6329.7330907393. The cubic root of 40065521 is about 342.1818196940.

The spelling of 40065521 in words is "forty million, sixty-five thousand, five hundred twenty-one".