206639701 has 4 divisors (see below), whose sum is σ = 206668672. Its totient is φ = 206610732.

The previous prime is 206639681. The next prime is 206639723. The reversal of 206639701 is 107936602.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 107936602 = 2 ⋅53968301.

It is a cyclic number.

It is not a de Polignac number, because 206639701 - 2⁵ = 206639669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206639201) 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 3 ways as a sum of consecutive naturals, for example, 4570 + ... + 20836.

It is an arithmetic number, because the mean of its divisors is an integer number (51667168).

Almost surely, 2^206639701 is an apocalyptic number.

It is an amenable number.

206639701 is a deficient number, since it is larger than the sum of its proper divisors (28971).

206639701 is a wasteful number, since it uses less digits than its factorization.

206639701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28970.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 206639701 is about 14374.9678608336. The cubic root of 206639701 is about 591.2047593541.

The spelling of 206639701 in words is "two hundred six million, six hundred thirty-nine thousand, seven hundred one".