208216078249 has 9 divisors (see below), whose sum is σ = 209358951543. Its totient is φ = 207079417512.

The previous prime is 208216078237. The next prime is 208216078271. The reversal of 208216078249 is 942870612802.

The square root of 208216078249 is 456307.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 60400435225 + 147815643024 = 245765^2 + 384468^2 .

It is not a de Polignac number, because 208216078249 - 2⁹ = 208216077737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (208216078219) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 90803947 + ... + 90806239.

It is an arithmetic number, because the mean of its divisors is an integer number (23262105727).

Almost surely, 2^208216078249 is an apocalyptic number.

208216078249 is the 456307-th square number.

208216078249 is the 228154-th centered octagonal number.

It is an amenable number.

208216078249 is a deficient number, since it is larger than the sum of its proper divisors (1142873294).

208216078249 is an frugal number, since it uses more digits than its factorization.

208216078249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4984 (or 2492 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 49.

Multiplying 208216078249 by its sum of digits (49), we get a square (10202587834201 = 3194149²).

The spelling of 208216078249 in words is "two hundred eight billion, two hundred sixteen million, seventy-eight thousand, two hundred forty-nine".