40821217 has 2 divisors, whose sum is σ = 40821218. Its totient is φ = 40821216.

The previous prime is 40821197. The next prime is 40821223. The reversal of 40821217 is 71212804.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36288576 + 4532641 = 6024^2 + 2129^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40821217 is a prime.

It is a super-2 number, since 2×40821217² = 3332743514722178, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 40821191 and 40821200.

It is not a weakly prime, because it can be changed into another prime (40821247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20410608 + 20410609.

It is an arithmetic number, because the mean of its divisors is an integer number (20410609).

Almost surely, 2^40821217 is an apocalyptic number.

It is an amenable number.

40821217 is a deficient number, since it is larger than the sum of its proper divisors (1).

40821217 is an equidigital number, since it uses as much as digits as its factorization.

40821217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 40821217 is about 6389.1483783052. The cubic root of 40821217 is about 344.3197883716.

The spelling of 40821217 in words is "forty million, eight hundred twenty-one thousand, two hundred seventeen".