206144781 has 8 divisors (see below), whose sum is σ = 274936800. Its totient is φ = 137391312.

The previous prime is 206144779. The next prime is 206144801. The reversal of 206144781 is 187441602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 206144781 - 2¹ = 206144779 is a prime.

It is a super-2 number, since 2×206144781² = 84991341467075922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206144711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6895 + ... + 21443.

It is an arithmetic number, because the mean of its divisors is an integer number (34367100).

Almost surely, 2^206144781 is an apocalyptic number.

It is an amenable number.

206144781 is a deficient number, since it is larger than the sum of its proper divisors (68792019).

206144781 is a wasteful number, since it uses less digits than its factorization.

206144781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19275.

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 206144781 is about 14357.7428936445. The cubic root of 206144781 is about 590.7323864761.

The spelling of 206144781 in words is "two hundred six million, one hundred forty-four thousand, seven hundred eighty-one".