209628706861 has 16 divisors (see below), whose sum is σ = 240398535168. Its totient is φ = 179065324800.

The previous prime is 209628706841. The next prime is 209628706883. The reversal of 209628706861 is 168607826902.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209628706861 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 (209628706841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3524076 + ... + 3583066.

It is an arithmetic number, because the mean of its divisors is an integer number (15024908448).

Almost surely, 2^209628706861 is an apocalyptic number.

It is an amenable number.

209628706861 is a deficient number, since it is larger than the sum of its proper divisors (30769828307).

209628706861 is a wasteful number, since it uses less digits than its factorization.

209628706861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60732.

The product of its (nonzero) digits is 3483648, while the sum is 55.

The spelling of 209628706861 in words is "two hundred nine billion, six hundred twenty-eight million, seven hundred six thousand, eight hundred sixty-one".