20678549 has 2 divisors, whose sum is σ = 20678550. Its totient is φ = 20678548.

The previous prime is 20678531. The next prime is 20678561. The reversal of 20678549 is 94587602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16056049 + 4622500 = 4007^2 + 2150^2 .

It is a cyclic number.

It is not a de Polignac number, because 20678549 - 2²⁴ = 3901333 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20678569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10339274 + 10339275.

It is an arithmetic number, because the mean of its divisors is an integer number (10339275).

Almost surely, 2^20678549 is an apocalyptic number.

It is an amenable number.

20678549 is a deficient number, since it is larger than the sum of its proper divisors (1).

20678549 is an equidigital number, since it uses as much as digits as its factorization.

20678549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 20678549 is about 4547.3672602947. The cubic root of 20678549 is about 274.4774606218.

The spelling of 20678549 in words is "twenty million, six hundred seventy-eight thousand, five hundred forty-nine".