40671821 has 2 divisors, whose sum is σ = 40671822. Its totient is φ = 40671820.

The previous prime is 40671793. The next prime is 40671823. The reversal of 40671821 is 12817604.

40671821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35880100 + 4791721 = 5990^2 + 2189^2 .

It is a cyclic number.

It is not a de Polignac number, because 40671821 - 2¹⁴ = 40655437 is a prime.

Together with 40671823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40671823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20335910 + 20335911.

It is an arithmetic number, because the mean of its divisors is an integer number (20335911).

Almost surely, 2^40671821 is an apocalyptic number.

It is an amenable number.

40671821 is a deficient number, since it is larger than the sum of its proper divisors (1).

40671821 is an equidigital number, since it uses as much as digits as its factorization.

40671821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 40671821 is about 6377.4462757439. The cubic root of 40671821 is about 343.8992319099.

It can be divided in two parts, 406 and 71821, that added together give a palindrome (72227).

The spelling of 40671821 in words is "forty million, six hundred seventy-one thousand, eight hundred twenty-one".