206620687961 has 8 divisors (see below), whose sum is σ = 214278582600. Its totient is φ = 198998329600.

The previous prime is 206620687913. The next prime is 206620687963. The reversal of 206620687961 is 169786026602.

It can be written as a sum of positive squares in 4 ways, for example, as 123088705600 + 83531982361 = 350840^2 + 289019^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206620687961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206620687963) 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, 8872226 + ... + 8895483.

It is an arithmetic number, because the mean of its divisors is an integer number (26784822825).

Almost surely, 2^206620687961 is an apocalyptic number.

It is an amenable number.

206620687961 is a deficient number, since it is larger than the sum of its proper divisors (7657894639).

206620687961 is a wasteful number, since it uses less digits than its factorization.

206620687961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17768139.

The product of its (nonzero) digits is 2612736, while the sum is 53.

The spelling of 206620687961 in words is "two hundred six billion, six hundred twenty million, six hundred eighty-seven thousand, nine hundred sixty-one".