1279717920 has 192 divisors, whose sum is σ = 4823763840. Its totient is φ = 314993664.

The previous prime is 1279717897. The next prime is 1279717921. The reversal of 1279717920 is 297179721.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (1279717921) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44767 + ... + 67553.

It is an arithmetic number, because the mean of its divisors is an integer number (25123770).

Almost surely, 2^1279717920 is an apocalyptic number.

1279717920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1279717920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2411881920).

1279717920 is an abundant number, since it is smaller than the sum of its proper divisors (3544045920).

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

1279717920 is a wasteful number, since it uses less digits than its factorization.

1279717920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22824 (or 22810 counting only the distinct ones).

The product of its (nonzero) digits is 111132, while the sum is 45.

The square root of 1279717920 is about 35773.1452349385. The cubic root of 1279717920 is about 1085.6872821407.

The spelling of 1279717920 in words is "one billion, two hundred seventy-nine million, seven hundred seventeen thousand, nine hundred twenty".