208349981 has 4 divisors (see below), whose sum is σ = 238114272. Its totient is φ = 178585692.

The previous prime is 208349969. The next prime is 208349983. The reversal of 208349981 is 189943802.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 189943802 = 2 ⋅94971901.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208349981 is a prime.

It is a super-2 number, since 2×208349981² = 86819429165400722, 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 (208349983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14882135 + ... + 14882148.

It is an arithmetic number, because the mean of its divisors is an integer number (59528568).

Almost surely, 2^208349981 is an apocalyptic number.

It is an amenable number.

208349981 is a deficient number, since it is larger than the sum of its proper divisors (29764291).

208349981 is an equidigital number, since it uses as much as digits as its factorization.

208349981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29764290.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 208349981 is about 14434.3334103103. Note that the first 3 decimals coincide. The cubic root of 208349981 is about 592.8313407209.

The spelling of 208349981 in words is "two hundred eight million, three hundred forty-nine thousand, nine hundred eighty-one".