40689421 has 2 divisors, whose sum is σ = 40689422. Its totient is φ = 40689420.

The previous prime is 40689413. The next prime is 40689433. The reversal of 40689421 is 12498604.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21206025 + 19483396 = 4605^2 + 4414^2 .

It is a cyclic number.

It is not a de Polignac number, because 40689421 - 2³ = 40689413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40689401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20344710 + 20344711.

It is an arithmetic number, because the mean of its divisors is an integer number (20344711).

Almost surely, 2^40689421 is an apocalyptic number.

It is an amenable number.

40689421 is a deficient number, since it is larger than the sum of its proper divisors (1).

40689421 is an equidigital number, since it uses as much as digits as its factorization.

40689421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 40689421 is about 6378.8259891613. The cubic root of 40689421 is about 343.9488301616.

The spelling of 40689421 in words is "forty million, six hundred eighty-nine thousand, four hundred twenty-one".