21422641 has 2 divisors, whose sum is σ = 21422642. Its totient is φ = 21422640.

The previous prime is 21422629. The next prime is 21422689. The reversal of 21422641 is 14622412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14288400 + 7134241 = 3780^2 + 2671^2 .

It is a cyclic number.

It is not a de Polignac number, because 21422641 - 2⁹ = 21422129 is a prime.

It is not a weakly prime, because it can be changed into another prime (21422341) 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, 10711320 + 10711321.

It is an arithmetic number, because the mean of its divisors is an integer number (10711321).

Almost surely, 2^21422641 is an apocalyptic number.

It is an amenable number.

21422641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422641 is an equidigital number, since it uses as much as digits as its factorization.

21422641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 768, while the sum is 22.

The square root of 21422641 is about 4628.4598950407. The cubic root of 21422641 is about 277.7309864237.

The spelling of 21422641 in words is "twenty-one million, four hundred twenty-two thousand, six hundred forty-one".