1271020205 has 16 divisors (see below), whose sum is σ = 1877199744. Its totient is φ = 804513600.

The previous prime is 1271020183. The next prime is 1271020279. The reversal of 1271020205 is 5020201721.

It is not a de Polignac number, because 1271020205 - 2²⁶ = 1203911341 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1396271 + ... + 1397180.

It is an arithmetic number, because the mean of its divisors is an integer number (117324984).

Almost surely, 2^1271020205 is an apocalyptic number.

It is an amenable number.

1271020205 is a deficient number, since it is larger than the sum of its proper divisors (606179539).

1271020205 is a wasteful number, since it uses less digits than its factorization.

1271020205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2793476.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 1271020205 is about 35651.3703102700. The cubic root of 1271020205 is about 1083.2220323261. Note that the first 3 decimals are identical.

Adding to 1271020205 its reverse (5020201721), we get a palindrome (6291221926).

The spelling of 1271020205 in words is "one billion, two hundred seventy-one million, twenty thousand, two hundred five".