21676129 has 2 divisors, whose sum is σ = 21676130. Its totient is φ = 21676128.

The previous prime is 21676111. The next prime is 21676141. The reversal of 21676129 is 92167612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14837904 + 6838225 = 3852^2 + 2615^2 .

It is a cyclic number.

It is not a de Polignac number, because 21676129 - 2¹⁵ = 21643361 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21676094 and 21676103.

It is not a weakly prime, because it can be changed into another prime (21676199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10838064 + 10838065.

It is an arithmetic number, because the mean of its divisors is an integer number (10838065).

Almost surely, 2^21676129 is an apocalyptic number.

It is an amenable number.

21676129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21676129 is an equidigital number, since it uses as much as digits as its factorization.

21676129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 34.

The square root of 21676129 is about 4655.7629879537. The cubic root of 21676129 is about 278.8221311185.

The spelling of 21676129 in words is "twenty-one million, six hundred seventy-six thousand, one hundred twenty-nine".