1608731897 has 2 divisors, whose sum is σ = 1608731898. Its totient is φ = 1608731896.

The previous prime is 1608731863. The next prime is 1608731899. The reversal of 1608731897 is 7981378061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1608731881 + 16 = 40109^2 + 4^2 .

It is a cyclic number.

It is not a de Polignac number, because 1608731897 - 2²⁰ = 1607683321 is a prime.

Together with 1608731899, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1608731899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 804365948 + 804365949.

It is an arithmetic number, because the mean of its divisors is an integer number (804365949).

Almost surely, 2^1608731897 is an apocalyptic number.

It is an amenable number.

1608731897 is a deficient number, since it is larger than the sum of its proper divisors (1).

1608731897 is an equidigital number, since it uses as much as digits as its factorization.

1608731897 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 508032, while the sum is 50.

The square root of 1608731897 is about 40109.0001994565. Note that the first 3 decimals coincide. The cubic root of 1608731897 is about 1171.7309215526.

The spelling of 1608731897 in words is "one billion, six hundred eight million, seven hundred thirty-one thousand, eight hundred ninety-seven".