21487783 has 2 divisors, whose sum is σ = 21487784. Its totient is φ = 21487782.

The previous prime is 21487751. The next prime is 21487891. The reversal of 21487783 is 38778412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21487783 - 2⁵ = 21487751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21487183) 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, 10743891 + 10743892.

It is an arithmetic number, because the mean of its divisors is an integer number (10743892).

Almost surely, 2^21487783 is an apocalyptic number.

21487783 is a deficient number, since it is larger than the sum of its proper divisors (1).

21487783 is an equidigital number, since it uses as much as digits as its factorization.

21487783 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75264, while the sum is 40.

The square root of 21487783 is about 4635.4916675580. The cubic root of 21487783 is about 278.0122098393.

The spelling of 21487783 in words is "twenty-one million, four hundred eighty-seven thousand, seven hundred eighty-three".