45040021 has 24 divisors (see below), whose sum is σ = 52690824. Its totient is φ = 38338560.

The previous prime is 45040001. The next prime is 45040081. The reversal of 45040021 is 12004054.

45040021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 12 ways, for example, as 14668900 + 30371121 = 3830^2 + 5511^2 .

It is not a de Polignac number, because 45040021 - 2⁹ = 45039509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 45039977 and 45040004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (45040001) 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 23 ways as a sum of consecutive naturals, for example, 175125 + ... + 175381.

It is an arithmetic number, because the mean of its divisors is an integer number (2195451).

Almost surely, 2^45040021 is an apocalyptic number.

It is an amenable number.

45040021 is a deficient number, since it is larger than the sum of its proper divisors (7650803).

45040021 is a wasteful number, since it uses less digits than its factorization.

45040021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361 (or 348 counting only the distinct ones).

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

The square root of 45040021 is about 6711.1862587772. The cubic root of 45040021 is about 355.7947439658.

Adding to 45040021 its reverse (12004054), we get a palindrome (57044075).

It can be divided in two parts, 4 and 5040021, that added together give a square (5040025 = 2245²).

The spelling of 45040021 in words is "forty-five million, forty thousand, twenty-one".