40021001 has 2 divisors, whose sum is σ = 40021002. Its totient is φ = 40021000.

The previous prime is 40020997. The next prime is 40021021. The reversal of 40021001 is 10012004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40005625 + 15376 = 6325^2 + 124^2 .

It is a cyclic number.

It is not a de Polignac number, because 40021001 - 2² = 40020997 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 40021001.

It is not a weakly prime, because it can be changed into another prime (40021021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20010500 + 20010501.

It is an arithmetic number, because the mean of its divisors is an integer number (20010501).

Almost surely, 2^40021001 is an apocalyptic number.

It is an amenable number.

40021001 is a deficient number, since it is larger than the sum of its proper divisors (1).

40021001 is an equidigital number, since it uses as much as digits as its factorization.

40021001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 40021001 is about 6326.2153773010. The cubic root of 40021001 is about 342.0550308719.

Adding to 40021001 its reverse (10012004), we get a palindrome (50033005).

The spelling of 40021001 in words is "forty million, twenty-one thousand, one".