1279129905 has 24 divisors (see below), whose sum is σ = 2288682240. Its totient is φ = 660195360.

The previous prime is 1279129877. The next prime is 1279129921. The reversal of 1279129905 is 5099219721.

It is not a de Polignac number, because 1279129905 - 2¹³ = 1279121713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 457075 + ... + 459864.

It is an arithmetic number, because the mean of its divisors is an integer number (95361760).

Almost surely, 2^1279129905 is an apocalyptic number.

1279129905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1279129905 is a deficient number, since it is larger than the sum of its proper divisors (1009552335).

1279129905 is a wasteful number, since it uses less digits than its factorization.

1279129905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916981 (or 916978 counting only the distinct ones).

The product of its (nonzero) digits is 102060, while the sum is 45.

The square root of 1279129905 is about 35764.9256255343. The cubic root of 1279129905 is about 1085.5209699138.

The spelling of 1279129905 in words is "one billion, two hundred seventy-nine million, one hundred twenty-nine thousand, nine hundred five".