40202021 has 2 divisors, whose sum is σ = 40202022. Its totient is φ = 40202020.

The previous prime is 40202003. The next prime is 40202047. The reversal of 40202021 is 12020204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38925121 + 1276900 = 6239^2 + 1130^2 .

It is a cyclic number.

It is not a de Polignac number, because 40202021 - 2¹⁰ = 40200997 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 40201993 and 40202011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40202051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20101010 + 20101011.

It is an arithmetic number, because the mean of its divisors is an integer number (20101011).

Almost surely, 2^40202021 is an apocalyptic number.

It is an amenable number.

40202021 is a deficient number, since it is larger than the sum of its proper divisors (1).

40202021 is an equidigital number, since it uses as much as digits as its factorization.

40202021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 40202021 is about 6340.5063677911. The cubic root of 40202021 is about 342.5699745142.

Adding to 40202021 its reverse (12020204), we get a palindrome (52222225).

The spelling of 40202021 in words is "forty million, two hundred two thousand, twenty-one".