208221157 has 2 divisors, whose sum is σ = 208221158. Its totient is φ = 208221156.

The previous prime is 208221109. The next prime is 208221161. The reversal of 208221157 is 751122802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 186978276 + 21242881 = 13674^2 + 4609^2 .

It is a cyclic number.

It is not a de Polignac number, because 208221157 - 2¹⁵ = 208188389 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208221557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104110578 + 104110579.

It is an arithmetic number, because the mean of its divisors is an integer number (104110579).

Almost surely, 2^208221157 is an apocalyptic number.

It is an amenable number.

208221157 is a deficient number, since it is larger than the sum of its proper divisors (1).

208221157 is an equidigital number, since it uses as much as digits as its factorization.

208221157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 208221157 is about 14429.8703043375. The cubic root of 208221157 is about 592.7091318460.

Adding to 208221157 its reverse (751122802), we get a palindrome (959343959).

The spelling of 208221157 in words is "two hundred eight million, two hundred twenty-one thousand, one hundred fifty-seven".