1271320155 has 96 divisors (see below), whose sum is σ = 2633140224. Its totient is φ = 555303168.

The previous prime is 1271320139. The next prime is 1271320201. The reversal of 1271320155 is 5510231721.

It is not a de Polignac number, because 1271320155 - 2⁴ = 1271320139 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 635617 + ... + 637613.

It is an arithmetic number, because the mean of its divisors is an integer number (27428544).

Almost surely, 2^1271320155 is an apocalyptic number.

1271320155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1271320155 is an abundant number, since it is smaller than the sum of its proper divisors (1361820069).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1271320155 is a wasteful number, since it uses less digits than its factorization.

1271320155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2105 (or 2102 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The square root of 1271320155 is about 35655.5767727855. The cubic root of 1271320155 is about 1083.3072360314.

Adding to 1271320155 its reverse (5510231721), we get a palindrome (6781551876).

The spelling of 1271320155 in words is "one billion, two hundred seventy-one million, three hundred twenty thousand, one hundred fifty-five".