40115521 has 4 divisors (see below), whose sum is σ = 40129200. Its totient is φ = 40101844.

The previous prime is 40115503. The next prime is 40115527. The reversal of 40115521 is 12551104.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 40115521 - 2¹³ = 40107329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40115527) 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, 451 + ... + 8968.

It is an arithmetic number, because the mean of its divisors is an integer number (10032300).

Almost surely, 2^40115521 is an apocalyptic number.

It is an amenable number.

40115521 is a deficient number, since it is larger than the sum of its proper divisors (13679).

40115521 is an equidigital number, since it uses as much as digits as its factorization.

40115521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13678.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 40115521 is about 6333.6814728876. The cubic root of 40115521 is about 342.3241031201.

Adding to 40115521 its reverse (12551104), we get a palindrome (52666625).

The spelling of 40115521 in words is "forty million, one hundred fifteen thousand, five hundred twenty-one".