206640626 has 4 divisors (see below), whose sum is σ = 309960942. Its totient is φ = 103320312.

The previous prime is 206640617. The next prime is 206640667. The reversal of 206640626 is 626046602.

It is a Cunningham number, because it is equal to 14375²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 206640625 + 1 = 14375^2 + 1^2 .

It is a junction number, because it is equal to n+sod(n) for n = 206640592 and 206640601.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 51660155 + ... + 51660158.

Almost surely, 2^206640626 is an apocalyptic number.

206640626 is a deficient number, since it is larger than the sum of its proper divisors (103320316).

206640626 is a wasteful number, since it uses less digits than its factorization.

206640626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103320315.

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 206640626 is about 14375.0000347826. Note that the first 4 decimals coincide. The cubic root of 206640626 is about 591.2056415073.

The spelling of 206640626 in words is "two hundred six million, six hundred forty thousand, six hundred twenty-six".