206851655 has 4 divisors (see below), whose sum is σ = 248221992. Its totient is φ = 165481320.

The previous prime is 206851649. The next prime is 206851661. The reversal of 206851655 is 556158602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 556158602 = 2 ⋅278079301.

It is an interprime number because it is at equal distance from previous prime (206851649) and next prime (206851661).

It is not a de Polignac number, because 206851655 - 2⁶ = 206851591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 20685161 + ... + 20685170.

It is an arithmetic number, because the mean of its divisors is an integer number (62055498).

Almost surely, 2^206851655 is an apocalyptic number.

206851655 is a deficient number, since it is larger than the sum of its proper divisors (41370337).

206851655 is an equidigital number, since it uses as much as digits as its factorization.

206851655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41370336.

The product of its (nonzero) digits is 72000, while the sum is 38.

The square root of 206851655 is about 14382.3383008466. The cubic root of 206851655 is about 591.4068266783.

It can be divided in two parts, 20685 and 1655, that multiplied together give a triangular number (34233675 = T₈₂₇₄).

The spelling of 206851655 in words is "two hundred six million, eight hundred fifty-one thousand, six hundred fifty-five".