209742125281 has 8 divisors (see below), whose sum is σ = 226889035520. Its totient is φ = 192739915152.

The previous prime is 209742125261. The next prime is 209742125287. The reversal of 209742125281 is 182521247902.

209742125281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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-209742125281 is a prime.

It is a super-2 number, since 2×209742125281² (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 (209742125287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36172011 + ... + 36177808.

It is an arithmetic number, because the mean of its divisors is an integer number (28361129440).

Almost surely, 2^209742125281 is an apocalyptic number.

It is an amenable number.

209742125281 is a deficient number, since it is larger than the sum of its proper divisors (17146910239).

209742125281 is a wasteful number, since it uses less digits than its factorization.

209742125281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72350055.

The product of its (nonzero) digits is 161280, while the sum is 43.

The spelling of 209742125281 in words is "two hundred nine billion, seven hundred forty-two million, one hundred twenty-five thousand, two hundred eighty-one".