40045021 has 4 divisors (see below), whose sum is σ = 40552000. Its totient is φ = 39538044.

The previous prime is 40045009. The next prime is 40045037. The reversal of 40045021 is 12054004.

40045021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 40045021 - 2⁹ = 40044509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40044986 and 40045004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40045121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 253371 + ... + 253528.

It is an arithmetic number, because the mean of its divisors is an integer number (10138000).

Almost surely, 2^40045021 is an apocalyptic number.

It is an amenable number.

40045021 is a deficient number, since it is larger than the sum of its proper divisors (506979).

40045021 is an equidigital number, since it uses as much as digits as its factorization.

40045021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506978.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 40045021 is about 6328.1135419649. The cubic root of 40045021 is about 342.1234492726.

Adding to 40045021 its reverse (12054004), we get a palindrome (52099025).

It can be divided in two parts, 4004 and 5021, that added together give a square (9025 = 95²).

The spelling of 40045021 in words is "forty million, forty-five thousand, twenty-one".