208918381 has 8 divisors (see below), whose sum is σ = 244316864. Its totient is φ = 174908160.

The previous prime is 208918379. The next prime is 208918397. The reversal of 208918381 is 183819802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 208918381 - 2¹ = 208918379 is a prime.

It is a super-2 number, since 2×208918381² = 87293779839322322, which 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 (208918301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 346740 + ... + 347341.

It is an arithmetic number, because the mean of its divisors is an integer number (30539608).

Almost surely, 2^208918381 is an apocalyptic number.

It is an amenable number.

208918381 is a deficient number, since it is larger than the sum of its proper divisors (35398483).

208918381 is an equidigital number, since it uses as much as digits as its factorization.

208918381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 694131.

The product of its (nonzero) digits is 27648, while the sum is 40.

The square root of 208918381 is about 14454.0091670097. The cubic root of 208918381 is about 593.3699526768.

The spelling of 208918381 in words is "two hundred eight million, nine hundred eighteen thousand, three hundred eighty-one".