208920891 has 8 divisors (see below), whose sum is σ = 290672640. Its totient is φ = 133224872.

The previous prime is 208920889. The next prime is 208920923. The reversal of 208920891 is 198029802.

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

It is a cyclic number.

It is not a de Polignac number, because 208920891 - 2¹ = 208920889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (208920851) 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, 1513851 + ... + 1513988.

It is an arithmetic number, because the mean of its divisors is an integer number (36334080).

Almost surely, 2^208920891 is an apocalyptic number.

208920891 is a deficient number, since it is larger than the sum of its proper divisors (81751749).

208920891 is a wasteful number, since it uses less digits than its factorization.

208920891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3027865.

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 208920891 is about 14454.0959938697. The cubic root of 208920891 is about 593.3723289678.

The spelling of 208920891 in words is "two hundred eight million, nine hundred twenty thousand, eight hundred ninety-one".