40397221 has 2 divisors, whose sum is σ = 40397222. Its totient is φ = 40397220.

The previous prime is 40397207. The next prime is 40397243. The reversal of 40397221 is 12279304.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23872996 + 16524225 = 4886^2 + 4065^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40397221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 40397221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40397281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20198610 + 20198611.

It is an arithmetic number, because the mean of its divisors is an integer number (20198611).

Almost surely, 2^40397221 is an apocalyptic number.

It is an amenable number.

40397221 is a deficient number, since it is larger than the sum of its proper divisors (1).

40397221 is an equidigital number, since it uses as much as digits as its factorization.

40397221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 40397221 is about 6355.8808201539. The cubic root of 40397221 is about 343.1235264695.

The spelling of 40397221 in words is "forty million, three hundred ninety-seven thousand, two hundred twenty-one".