208042391 has 8 divisors (see below), whose sum is σ = 212051904. Its totient is φ = 204052320.

The previous prime is 208042369. The next prime is 208042403. The reversal of 208042391 is 193240802.

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

It is not a de Polignac number, because 208042391 - 2⁶ = 208042327 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 (208042321) 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, 17741 + ... + 27033.

It is an arithmetic number, because the mean of its divisors is an integer number (26506488).

Almost surely, 2^208042391 is an apocalyptic number.

208042391 is a deficient number, since it is larger than the sum of its proper divisors (4009513).

208042391 is an equidigital number, since it uses as much as digits as its factorization.

208042391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9721.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 208042391 is about 14423.6746704853. The cubic root of 208042391 is about 592.5394619637.

The spelling of 208042391 in words is "two hundred eight million, forty-two thousand, three hundred ninety-one".