209481983877 has 4 divisors (see below), whose sum is σ = 279309311840. Its totient is φ = 139654655916.

The previous prime is 209481983869. The next prime is 209481983903. The reversal of 209481983877 is 778389184902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 209481983877 - 2³ = 209481983869 is a prime.

It is a super-2 number, since 2×209481983877² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209481983377) 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, 34913663977 + ... + 34913663982.

It is an arithmetic number, because the mean of its divisors is an integer number (69827327960).

Almost surely, 2^209481983877 is an apocalyptic number.

It is an amenable number.

209481983877 is a deficient number, since it is larger than the sum of its proper divisors (69827327963).

209481983877 is an equidigital number, since it uses as much as digits as its factorization.

209481983877 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69827327962.

The product of its (nonzero) digits is 48771072, while the sum is 66.

The spelling of 209481983877 in words is "two hundred nine billion, four hundred eighty-one million, nine hundred eighty-three thousand, eight hundred seventy-seven".