20671529 has 2 divisors, whose sum is σ = 20671530. Its totient is φ = 20671528.

The previous prime is 20671517. The next prime is 20671531. The reversal of 20671529 is 92517602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18490000 + 2181529 = 4300^2 + 1477^2 .

It is a cyclic number.

It is not a de Polignac number, because 20671529 - 2¹² = 20667433 is a prime.

It is a super-2 number, since 2×20671529² = 854624222395682, which contains 22 as substring.

Together with 20671531, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20671495 and 20671504.

It is not a weakly prime, because it can be changed into another prime (20671129) 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, 10335764 + 10335765.

It is an arithmetic number, because the mean of its divisors is an integer number (10335765).

Almost surely, 2^20671529 is an apocalyptic number.

It is an amenable number.

20671529 is a deficient number, since it is larger than the sum of its proper divisors (1).

20671529 is an equidigital number, since it uses as much as digits as its factorization.

20671529 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 20671529 is about 4546.5953195771. The cubic root of 20671529 is about 274.4463970326.

The spelling of 20671529 in words is "twenty million, six hundred seventy-one thousand, five hundred twenty-nine".