206138935091 has 2 divisors, whose sum is σ = 206138935092. Its totient is φ = 206138935090.

The previous prime is 206138935061. The next prime is 206138935129. The reversal of 206138935091 is 190539831602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206138935091 is a prime.

It is a super-2 number, since 2×206138935091² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (206138935061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103069467545 + 103069467546.

It is an arithmetic number, because the mean of its divisors is an integer number (103069467546).

Almost surely, 2^206138935091 is an apocalyptic number.

206138935091 is a deficient number, since it is larger than the sum of its proper divisors (1).

206138935091 is an equidigital number, since it uses as much as digits as its factorization.

206138935091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 349920, while the sum is 47.

The spelling of 206138935091 in words is "two hundred six billion, one hundred thirty-eight million, nine hundred thirty-five thousand, ninety-one".