208693621 has 2 divisors, whose sum is σ = 208693622. Its totient is φ = 208693620.

The previous prime is 208693619. The next prime is 208693631. The reversal of 208693621 is 126396802.

208693621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 149572900 + 59120721 = 12230^2 + 7689^2 .

It is a cyclic number.

It is not a de Polignac number, because 208693621 - 2¹ = 208693619 is a prime.

Together with 208693619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208693631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104346810 + 104346811.

It is an arithmetic number, because the mean of its divisors is an integer number (104346811).

Almost surely, 2^208693621 is an apocalyptic number.

It is an amenable number.

208693621 is a deficient number, since it is larger than the sum of its proper divisors (1).

208693621 is an equidigital number, since it uses as much as digits as its factorization.

208693621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 208693621 is about 14446.2320692975. The cubic root of 208693621 is about 593.1570885514.

The spelling of 208693621 in words is "two hundred eight million, six hundred ninety-three thousand, six hundred twenty-one".