21284677 has 2 divisors, whose sum is σ = 21284678. Its totient is φ = 21284676.

The previous prime is 21284671. The next prime is 21284687. The reversal of 21284677 is 77648212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20061441 + 1223236 = 4479^2 + 1106^2 .

It is a cyclic number.

It is not a de Polignac number, because 21284677 - 2¹¹ = 21282629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21284671) 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, 10642338 + 10642339.

It is an arithmetic number, because the mean of its divisors is an integer number (10642339).

Almost surely, 2^21284677 is an apocalyptic number.

It is an amenable number.

21284677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21284677 is an equidigital number, since it uses as much as digits as its factorization.

21284677 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37632, while the sum is 37.

The square root of 21284677 is about 4613.5319441833. The cubic root of 21284677 is about 277.1334966270.

The spelling of 21284677 in words is "twenty-one million, two hundred eighty-four thousand, six hundred seventy-seven".