400416221 has 2 divisors, whose sum is σ = 400416222. Its totient is φ = 400416220.

The previous prime is 400416199. The next prime is 400416227. The reversal of 400416221 is 122614004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 260467321 + 139948900 = 16139^2 + 11830^2 .

It is a cyclic number.

It is not a de Polignac number, because 400416221 - 2⁶ = 400416157 is a prime.

It is a super-3 number, since 3×400416221³ (a number of 27 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 400416193 and 400416202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400416227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200208110 + 200208111.

It is an arithmetic number, because the mean of its divisors is an integer number (200208111).

Almost surely, 2^400416221 is an apocalyptic number.

It is an amenable number.

400416221 is a deficient number, since it is larger than the sum of its proper divisors (1).

400416221 is an equidigital number, since it uses as much as digits as its factorization.

400416221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 400416221 is about 20010.4028195336. The cubic root of 400416221 is about 737.0617730165.

The spelling of 400416221 in words is "four hundred million, four hundred sixteen thousand, two hundred twenty-one".