208215851981279 has 4 divisors (see below), whose sum is σ = 208215992893080. Its totient is φ = 208215711069480.

The previous prime is 208215851981227. The next prime is 208215851981299. The reversal of 208215851981279 is 972189158512802.

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

It is a cyclic number.

It is not a de Polignac number, because 208215851981279 - 2³² = 208211557013983 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 (208215851981209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68215709 + ... + 71202630.

It is an arithmetic number, because the mean of its divisors is an integer number (52053998223270).

Almost surely, 2^{208215851981279} is an apocalyptic number.

208215851981279 is a deficient number, since it is larger than the sum of its proper divisors (140911801).

208215851981279 is a wasteful number, since it uses less digits than its factorization.

208215851981279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140911800.

The product of its (nonzero) digits is 58060800, while the sum is 68.

The spelling of 208215851981279 in words is "two hundred eight trillion, two hundred fifteen billion, eight hundred fifty-one million, nine hundred eighty-one thousand, two hundred seventy-nine".