209120551 has 2 divisors, whose sum is σ = 209120552. Its totient is φ = 209120550.

The previous prime is 209120539. The next prime is 209120557. The reversal of 209120551 is 155021902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 209120551 - 2⁷ = 209120423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209120557) 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, 104560275 + 104560276.

It is an arithmetic number, because the mean of its divisors is an integer number (104560276).

Almost surely, 2^209120551 is an apocalyptic number.

209120551 is a deficient number, since it is larger than the sum of its proper divisors (1).

209120551 is an equidigital number, since it uses as much as digits as its factorization.

209120551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 209120551 is about 14461.0010372726. The cubic root of 209120551 is about 593.5612920378.

The spelling of 209120551 in words is "two hundred nine million, one hundred twenty thousand, five hundred fifty-one".