40836821 has 2 divisors, whose sum is σ = 40836822. Its totient is φ = 40836820.

The previous prime is 40836787. The next prime is 40836841. The reversal of 40836821 is 12863804.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39866596 + 970225 = 6314^2 + 985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40836821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40836841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20418410 + 20418411.

It is an arithmetic number, because the mean of its divisors is an integer number (20418411).

Almost surely, 2^40836821 is an apocalyptic number.

It is an amenable number.

40836821 is a deficient number, since it is larger than the sum of its proper divisors (1).

40836821 is an equidigital number, since it uses as much as digits as its factorization.

40836821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 40836821 is about 6390.3693946438. The cubic root of 40836821 is about 344.3636551149.

The spelling of 40836821 in words is "forty million, eight hundred thirty-six thousand, eight hundred twenty-one".