1279129728 has 64 divisors (see below), whose sum is σ = 3545438400. Its totient is φ = 407835648.

The previous prime is 1279129727. The next prime is 1279129867. The reversal of 1279129728 is 8279219721.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×1279129728² = 3272345722106707968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (1279129727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63583 + ... + 81246.

It is an arithmetic number, because the mean of its divisors is an integer number (55397475).

Almost surely, 2^1279129728 is an apocalyptic number.

It is an amenable number.

1279129728 is an abundant number, since it is smaller than the sum of its proper divisors (2266308672).

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

1279129728 is a wasteful number, since it uses less digits than its factorization.

1279129728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144869 (or 144857 counting only the distinct ones).

The product of its digits is 254016, while the sum is 48.

The square root of 1279129728 is about 35764.9231510428. The cubic root of 1279129728 is about 1085.5209198440.

The spelling of 1279129728 in words is "one billion, two hundred seventy-nine million, one hundred twenty-nine thousand, seven hundred twenty-eight".