208921901 has 4 divisors (see below), whose sum is σ = 209393952. Its totient is φ = 208449852.

The previous prime is 208921897. The next prime is 208921913. The reversal of 208921901 is 109129802.

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.

It is a cyclic number.

It is not a de Polignac number, because 208921901 - 2² = 208921897 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 (208921961) 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, 235361 + ... + 236246.

It is an arithmetic number, because the mean of its divisors is an integer number (52348488).

Almost surely, 2^208921901 is an apocalyptic number.

It is an amenable number.

208921901 is a deficient number, since it is larger than the sum of its proper divisors (472051).

208921901 is an equidigital number, since it uses as much as digits as its factorization.

208921901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472050.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 208921901 is about 14454.1309320208. The cubic root of 208921901 is about 593.3732851593.

The spelling of 208921901 in words is "two hundred eight million, nine hundred twenty-one thousand, nine hundred one".