40001521 has 4 divisors (see below), whose sum is σ = 45716032. Its totient is φ = 34287012.

The previous prime is 40001519. The next prime is 40001557. The reversal of 40001521 is 12510004.

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 40001521 - 2¹ = 40001519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40001581) 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, 2857245 + ... + 2857258.

It is an arithmetic number, because the mean of its divisors is an integer number (11429008).

Almost surely, 2^40001521 is an apocalyptic number.

It is an amenable number.

40001521 is a deficient number, since it is larger than the sum of its proper divisors (5714511).

40001521 is an equidigital number, since it uses as much as digits as its factorization.

40001521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5714510.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 40001521 is about 6324.6755648017. The cubic root of 40001521 is about 341.9995240694. Note that the first 3 decimals are identical.

Adding to 40001521 its reverse (12510004), we get a palindrome (52511525).

The spelling of 40001521 in words is "forty million, one thousand, five hundred twenty-one".