1279999998 has 12 divisors (see below), whose sum is σ = 2773333368. Its totient is φ = 426666660.

The previous prime is 1279999997. The next prime is 1280000003. The reversal of 1279999998 is 8999999721.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1279999991) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35555538 + ... + 35555573.

It is an arithmetic number, because the mean of its divisors is an integer number (231111114).

Almost surely, 2^1279999998 is an apocalyptic number.

1279999998 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1279999998 is an abundant number, since it is smaller than the sum of its proper divisors (1493333370).

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

1279999998 is a wasteful number, since it uses less digits than its factorization.

1279999998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71111119 (or 71111116 counting only the distinct ones).

The product of its digits is 59521392, while the sum is 72.

The square root of 1279999998 is about 35777.0876120458. The cubic root of 1279999998 is about 1085.7670460725.

The spelling of 1279999998 in words is "one billion, two hundred seventy-nine million, nine hundred ninety-nine thousand, nine hundred ninety-eight".