40220021 has 2 divisors, whose sum is σ = 40220022. Its totient is φ = 40220020.

The previous prime is 40219997. The next prime is 40220027. The reversal of 40220021 is 12002204.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36663025 + 3556996 = 6055^2 + 1886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40220021 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 = 40219984 and 40220011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40220027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20110010 + 20110011.

It is an arithmetic number, because the mean of its divisors is an integer number (20110011).

Almost surely, 2^40220021 is an apocalyptic number.

It is an amenable number.

40220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

40220021 is an equidigital number, since it uses as much as digits as its factorization.

40220021 is an odious number, because the sum of its binary digits is odd.

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

The square root of 40220021 is about 6341.9256539319. The cubic root of 40220021 is about 342.6210941621.

Adding to 40220021 its reverse (12002204), we get a palindrome (52222225).

The spelling of 40220021 in words is "forty million, two hundred twenty thousand, twenty-one".