40208221 has 2 divisors, whose sum is σ = 40208222. Its totient is φ = 40208220.

The previous prime is 40208219. The next prime is 40208227. The reversal of 40208221 is 12280204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25300900 + 14907321 = 5030^2 + 3861^2 .

It is a cyclic number.

It is not a de Polignac number, because 40208221 - 2¹ = 40208219 is a prime.

Together with 40208219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40208227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20104110 + 20104111.

It is an arithmetic number, because the mean of its divisors is an integer number (20104111).

Almost surely, 2^40208221 is an apocalyptic number.

It is an amenable number.

40208221 is a deficient number, since it is larger than the sum of its proper divisors (1).

40208221 is an equidigital number, since it uses as much as digits as its factorization.

40208221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 40208221 is about 6340.9952688833. The cubic root of 40208221 is about 342.5875841154.

Adding to 40208221 its reverse (12280204), we get a palindrome (52488425).

The spelling of 40208221 in words is "forty million, two hundred eight thousand, two hundred twenty-one".