1271920897 has 4 divisors (see below), whose sum is σ = 1369760980. Its totient is φ = 1174080816.

The previous prime is 1271920883. The next prime is 1271920919. The reversal of 1271920897 is 7980291721.

It is a Cunningham number, because it is equal to 35664²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 188128656 + 1083792241 = 13716^2 + 32921^2 .

It is a cyclic number.

It is not a de Polignac number, because 1271920897 - 2¹¹ = 1271918849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1271924897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48920022 + ... + 48920047.

It is an arithmetic number, because the mean of its divisors is an integer number (342440245).

Almost surely, 2^1271920897 is an apocalyptic number.

It is an amenable number.

1271920897 is a deficient number, since it is larger than the sum of its proper divisors (97840083).

1271920897 is an equidigital number, since it uses as much as digits as its factorization.

1271920897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97840082.

The product of its (nonzero) digits is 127008, while the sum is 46.

The square root of 1271920897 is about 35664.0000140197. Note that the first 4 decimals coincide. The cubic root of 1271920897 is about 1083.4778423295.

The spelling of 1271920897 in words is "one billion, two hundred seventy-one million, nine hundred twenty thousand, eight hundred ninety-seven".