1687271897 has 2 divisors, whose sum is σ = 1687271898. Its totient is φ = 1687271896.

The previous prime is 1687271837. The next prime is 1687271983. The reversal of 1687271897 is 7981727861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1685841481 + 1430416 = 41059^2 + 1196^2 .

It is a cyclic number.

It is not a de Polignac number, because 1687271897 - 2¹⁰ = 1687270873 is a prime.

It is not a weakly prime, because it can be changed into another prime (1687271837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 843635948 + 843635949.

It is an arithmetic number, because the mean of its divisors is an integer number (843635949).

Almost surely, 2^1687271897 is an apocalyptic number.

It is an amenable number.

1687271897 is a deficient number, since it is larger than the sum of its proper divisors (1).

1687271897 is an equidigital number, since it uses as much as digits as its factorization.

1687271897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2370816, while the sum is 56.

The square root of 1687271897 is about 41076.4153377580. The cubic root of 1687271897 is about 1190.4971434564.

The spelling of 1687271897 in words is "one billion, six hundred eighty-seven million, two hundred seventy-one thousand, eight hundred ninety-seven".