209138560387 has 2 divisors, whose sum is σ = 209138560388. Its totient is φ = 209138560386.

The previous prime is 209138560343. The next prime is 209138560427. The reversal of 209138560387 is 783065831902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 209138560387 - 2¹¹ = 209138558339 is a prime.

It is not a weakly prime, because it can be changed into another prime (209138560327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104569280193 + 104569280194.

It is an arithmetic number, because the mean of its divisors is an integer number (104569280194).

Almost surely, 2^209138560387 is an apocalyptic number.

209138560387 is a deficient number, since it is larger than the sum of its proper divisors (1).

209138560387 is an equidigital number, since it uses as much as digits as its factorization.

209138560387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2177280, while the sum is 52.

The spelling of 209138560387 in words is "two hundred nine billion, one hundred thirty-eight million, five hundred sixty thousand, three hundred eighty-seven".