206412561661 has 8 divisors (see below), whose sum is σ = 213081147648. Its totient is φ = 199744608000.

The previous prime is 206412561637. The next prime is 206412561679. The reversal of 206412561661 is 166165214602.

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

It is a cyclic number.

It is not a de Polignac number, because 206412561661 - 2¹⁹ = 206412037373 is a prime.

It is a super-3 number, since 3×206412561661³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206412564661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 556701 + ... + 850141.

It is an arithmetic number, because the mean of its divisors is an integer number (26635143456).

Almost surely, 2^206412561661 is an apocalyptic number.

It is an amenable number.

206412561661 is a deficient number, since it is larger than the sum of its proper divisors (6668585987).

206412561661 is a wasteful number, since it uses less digits than its factorization.

206412561661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316163.

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 206412561661 in words is "two hundred six billion, four hundred twelve million, five hundred sixty-one thousand, six hundred sixty-one".