20708249 has 2 divisors, whose sum is σ = 20708250. Its totient is φ = 20708248.

The previous prime is 20708221. The next prime is 20708269. The reversal of 20708249 is 94280702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18361225 + 2347024 = 4285^2 + 1532^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20708249 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20708209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10354124 + 10354125.

It is an arithmetic number, because the mean of its divisors is an integer number (10354125).

Almost surely, 2^20708249 is an apocalyptic number.

It is an amenable number.

20708249 is a deficient number, since it is larger than the sum of its proper divisors (1).

20708249 is an equidigital number, since it uses as much as digits as its factorization.

20708249 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 20708249 is about 4550.6317143887. The cubic root of 20708249 is about 274.6088057640.

The spelling of 20708249 in words is "twenty million, seven hundred eight thousand, two hundred forty-nine".