206687743979 has 4 divisors (see below), whose sum is σ = 218845846584. Its totient is φ = 194529641376.

The previous prime is 206687743939. The next prime is 206687743987. The reversal of 206687743979 is 979347786602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 979347786602 = 2 ⋅489673893301.

It is a cyclic number.

It is not a de Polignac number, because 206687743979 - 2¹² = 206687739883 is a prime.

It is a super-2 number, since 2×206687743979² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206687743939) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6079051277 + ... + 6079051310.

It is an arithmetic number, because the mean of its divisors is an integer number (54711461646).

Almost surely, 2^206687743979 is an apocalyptic number.

206687743979 is a deficient number, since it is larger than the sum of its proper divisors (12158102605).

206687743979 is a wasteful number, since it uses less digits than its factorization.

206687743979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12158102604.

The product of its (nonzero) digits is 192036096, while the sum is 68.

The spelling of 206687743979 in words is "two hundred six billion, six hundred eighty-seven million, seven hundred forty-three thousand, nine hundred seventy-nine".