21486149 has 2 divisors, whose sum is σ = 21486150. Its totient is φ = 21486148.

The previous prime is 21486139. The next prime is 21486161. The reversal of 21486149 is 94168412.

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., 18335524 + 3150625 = 4282^2 + 1775^2 .

It is a cyclic number.

It is not a de Polignac number, because 21486149 - 2⁴ = 21486133 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21486119) 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, 10743074 + 10743075.

It is an arithmetic number, because the mean of its divisors is an integer number (10743075).

Almost surely, 2^21486149 is an apocalyptic number.

It is an amenable number.

21486149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21486149 is an equidigital number, since it uses as much as digits as its factorization.

21486149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 35.

The square root of 21486149 is about 4635.3154153736. The cubic root of 21486149 is about 278.0051626804.

The spelling of 21486149 in words is "twenty-one million, four hundred eighty-six thousand, one hundred forty-nine".