21084677 has 2 divisors, whose sum is σ = 21084678. Its totient is φ = 21084676.

The previous prime is 21084673. The next prime is 21084683. The reversal of 21084677 is 77648012.

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., 21077281 + 7396 = 4591^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 21084677 - 2² = 21084673 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21084673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10542338 + 10542339.

It is an arithmetic number, because the mean of its divisors is an integer number (10542339).

Almost surely, 2^21084677 is an apocalyptic number.

It is an amenable number.

21084677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21084677 is an equidigital number, since it uses as much as digits as its factorization.

21084677 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 21084677 is about 4591.8054183513. The cubic root of 21084677 is about 276.2627416439.

The spelling of 21084677 in words is "twenty-one million, eighty-four thousand, six hundred seventy-seven".