209981600321 has 4 divisors (see below), whose sum is σ = 209989013892. Its totient is φ = 209974186752.

The previous prime is 209981600303. The next prime is 209981600357. The reversal of 209981600321 is 123006189902.

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

It can be written as a sum of positive squares in 2 ways, for example, as 70153468225 + 139828132096 = 264865^2 + 373936^2 .

It is a cyclic number.

It is not a de Polignac number, because 209981600321 - 2²² = 209977406017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209981600821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3664136 + ... + 3721001.

It is an arithmetic number, because the mean of its divisors is an integer number (52497253473).

Almost surely, 2^209981600321 is an apocalyptic number.

It is an amenable number.

209981600321 is a deficient number, since it is larger than the sum of its proper divisors (7413571).

209981600321 is an equidigital number, since it uses as much as digits as its factorization.

209981600321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7413570.

The product of its (nonzero) digits is 46656, while the sum is 41.

The spelling of 209981600321 in words is "two hundred nine billion, nine hundred eighty-one million, six hundred thousand, three hundred twenty-one".