20552557 has 2 divisors, whose sum is σ = 20552558. Its totient is φ = 20552556.

The previous prime is 20552549. The next prime is 20552563. The reversal of 20552557 is 75525502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17816841 + 2735716 = 4221^2 + 1654^2 .

It is a cyclic number.

It is not a de Polignac number, because 20552557 - 2³ = 20552549 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 (20552527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10276278 + 10276279.

It is an arithmetic number, because the mean of its divisors is an integer number (10276279).

Almost surely, 2^20552557 is an apocalyptic number.

It is an amenable number.

20552557 is a deficient number, since it is larger than the sum of its proper divisors (1).

20552557 is an equidigital number, since it uses as much as digits as its factorization.

20552557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17500, while the sum is 31.

The square root of 20552557 is about 4533.4928035677. The cubic root of 20552557 is about 273.9188715003.

The spelling of 20552557 in words is "twenty million, five hundred fifty-two thousand, five hundred fifty-seven".