20550857 has 2 divisors, whose sum is σ = 20550858. Its totient is φ = 20550856.

The previous prime is 20550809. The next prime is 20550863. The reversal of 20550857 is 75805502.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14280841 + 6270016 = 3779^2 + 2504^2 .

It is a cyclic number.

It is not a de Polignac number, because 20550857 - 2¹⁶ = 20485321 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20550757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10275428 + 10275429.

It is an arithmetic number, because the mean of its divisors is an integer number (10275429).

Almost surely, 2^20550857 is an apocalyptic number.

It is an amenable number.

20550857 is a deficient number, since it is larger than the sum of its proper divisors (1).

20550857 is an equidigital number, since it uses as much as digits as its factorization.

20550857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14000, while the sum is 32.

The square root of 20550857 is about 4533.3053062859. The cubic root of 20550857 is about 273.9113189133.

The spelling of 20550857 in words is "twenty million, five hundred fifty thousand, eight hundred fifty-seven".