40205521 has 4 divisors (see below), whose sum is σ = 40228452. Its totient is φ = 40182592.

The previous prime is 40205509. The next prime is 40205537. The reversal of 40205521 is 12550204.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13424896 + 26780625 = 3664^2 + 5175^2 .

It is a cyclic number.

It is not a de Polignac number, because 40205521 - 2¹⁵ = 40172753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40205551) 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, 8596 + ... + 12421.

It is an arithmetic number, because the mean of its divisors is an integer number (10057113).

Almost surely, 2^40205521 is an apocalyptic number.

It is an amenable number.

40205521 is a deficient number, since it is larger than the sum of its proper divisors (22931).

40205521 is a wasteful number, since it uses less digits than its factorization.

40205521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22930.

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 40205521 is about 6340.7823649767. The cubic root of 40205521 is about 342.5799156406.

Adding to 40205521 its reverse (12550204), we get a palindrome (52755725).

The spelling of 40205521 in words is "forty million, two hundred five thousand, five hundred twenty-one".