20657149 has 2 divisors, whose sum is σ = 20657150. Its totient is φ = 20657148.

The previous prime is 20657141. The next prime is 20657171. The reversal of 20657149 is 94175602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18232900 + 2424249 = 4270^2 + 1557^2 .

It is a cyclic number.

It is not a de Polignac number, because 20657149 - 2³ = 20657141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20657141) 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, 10328574 + 10328575.

It is an arithmetic number, because the mean of its divisors is an integer number (10328575).

Almost surely, 2^20657149 is an apocalyptic number.

It is an amenable number.

20657149 is a deficient number, since it is larger than the sum of its proper divisors (1).

20657149 is an equidigital number, since it uses as much as digits as its factorization.

20657149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 20657149 is about 4545.0136413437. The cubic root of 20657149 is about 274.3827433849.

The spelling of 20657149 in words is "twenty million, six hundred fifty-seven thousand, one hundred forty-nine".