1271998605 has 16 divisors (see below), whose sum is σ = 2142313920. Its totient is φ = 642693888.

The previous prime is 1271998579. The next prime is 1271998613. The reversal of 1271998605 is 5068991721.

It is not a de Polignac number, because 1271998605 - 2⁵ = 1271998573 is a prime.

It is a super-2 number, since 2×1271998605² = 3235960902243892050, which contains 22 as substring.

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, 2231292 + ... + 2231861.

It is an arithmetic number, because the mean of its divisors is an integer number (133894620).

Almost surely, 2^1271998605 is an apocalyptic number.

1271998605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1271998605 is a deficient number, since it is larger than the sum of its proper divisors (870315315).

1271998605 is a wasteful number, since it uses less digits than its factorization.

1271998605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4463180.

The product of its (nonzero) digits is 272160, while the sum is 48.

The square root of 1271998605 is about 35665.0894433198. The cubic root of 1271998605 is about 1083.4999069044.

The spelling of 1271998605 in words is "one billion, two hundred seventy-one million, nine hundred ninety-eight thousand, six hundred five".