20550997 has 2 divisors, whose sum is σ = 20550998. Its totient is φ = 20550996.

The previous prime is 20550941. The next prime is 20551001. The reversal of 20550997 is 79905502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20439441 + 111556 = 4521^2 + 334^2 .

It is a cyclic number.

It is not a de Polignac number, because 20550997 - 2¹⁵ = 20518229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20550917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10275498 + 10275499.

It is an arithmetic number, because the mean of its divisors is an integer number (10275499).

Almost surely, 2^20550997 is an apocalyptic number.

It is an amenable number.

20550997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20550997 is an equidigital number, since it uses as much as digits as its factorization.

20550997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28350, while the sum is 37.

The square root of 20550997 is about 4533.3207475315. The cubic root of 20550997 is about 273.9119409068.

The spelling of 20550997 in words is "twenty million, five hundred fifty thousand, nine hundred ninety-seven".