206701561 has 4 divisors (see below), whose sum is σ = 225492624. Its totient is φ = 187910500.

The previous prime is 206701549. The next prime is 206701567. The reversal of 206701561 is 165107602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 206701561 - 2¹¹ = 206699513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206701567) by changing a digit.

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, 9395515 + ... + 9395536.

It is an arithmetic number, because the mean of its divisors is an integer number (56373156).

Almost surely, 2^206701561 is an apocalyptic number.

It is an amenable number.

206701561 is a deficient number, since it is larger than the sum of its proper divisors (18791063).

206701561 is a wasteful number, since it uses less digits than its factorization.

206701561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18791062.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 206701561 is about 14377.1193568114. The cubic root of 206701561 is about 591.2637481439.

The spelling of 206701561 in words is "two hundred six million, seven hundred one thousand, five hundred sixty-one".