40668421 has 2 divisors, whose sum is σ = 40668422. Its totient is φ = 40668420.

The previous prime is 40668409. The next prime is 40668427. The reversal of 40668421 is 12486604.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37039396 + 3629025 = 6086^2 + 1905^2 .

It is a cyclic number.

It is not a de Polignac number, because 40668421 - 2¹³ = 40660229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40668427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20334210 + 20334211.

It is an arithmetic number, because the mean of its divisors is an integer number (20334211).

Almost surely, 2^40668421 is an apocalyptic number.

It is an amenable number.

40668421 is a deficient number, since it is larger than the sum of its proper divisors (1).

40668421 is an equidigital number, since it uses as much as digits as its factorization.

40668421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 40668421 is about 6377.1797057947. The cubic root of 40668421 is about 343.8896487805.

The spelling of 40668421 in words is "forty million, six hundred sixty-eight thousand, four hundred twenty-one".