209081381 has 8 divisors (see below), whose sum is σ = 211947840. Its totient is φ = 206226592.

The previous prime is 209081359. The next prime is 209081423. The reversal of 209081381 is 183180902.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209081381 is a prime.

It is a super-2 number, since 2×209081381² = 87430047761734322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209081311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36776 + ... + 42078.

It is an arithmetic number, because the mean of its divisors is an integer number (26493480).

Almost surely, 2^209081381 is an apocalyptic number.

It is an amenable number.

209081381 is a deficient number, since it is larger than the sum of its proper divisors (2866459).

209081381 is an equidigital number, since it uses as much as digits as its factorization.

209081381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5835.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 209081381 is about 14459.6466416023. The cubic root of 209081381 is about 593.5242300856.

The spelling of 209081381 in words is "two hundred nine million, eighty-one thousand, three hundred eighty-one".