40121021 has 4 divisors (see below), whose sum is σ = 41054112. Its totient is φ = 39187932.

The previous prime is 40121009. The next prime is 40121023. The reversal of 40121021 is 12012104.

40121021 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 40121021 - 2¹⁸ = 39858877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40120993 and 40121011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40121023) 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, 466481 + ... + 466566.

It is an arithmetic number, because the mean of its divisors is an integer number (10263528).

Almost surely, 2^40121021 is an apocalyptic number.

It is an amenable number.

40121021 is a deficient number, since it is larger than the sum of its proper divisors (933091).

40121021 is an equidigital number, since it uses as much as digits as its factorization.

40121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933090.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 40121021 is about 6334.1156446658. The cubic root of 40121021 is about 342.3397470777.

Adding to 40121021 its reverse (12012104), we get a palindrome (52133125).

The spelling of 40121021 in words is "forty million, one hundred twenty-one thousand, twenty-one".