1298521728 has 192 divisors, whose sum is σ = 4293057600. Its totient is φ = 369045504.

The previous prime is 1298521717. The next prime is 1298521729. The reversal of 1298521728 is 8271258921.

1298521728 is a `hidden beast` number, since 12 + 98 + 521 + 7 + 28 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1298521729) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2281828 + ... + 2282396.

It is an arithmetic number, because the mean of its divisors is an integer number (22359675).

Almost surely, 2^1298521728 is an apocalyptic number.

1298521728 is a gapful number since it is divisible by the number (18) 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 1298521728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2146528800).

1298521728 is an abundant number, since it is smaller than the sum of its proper divisors (2994535872).

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

1298521728 is a wasteful number, since it uses less digits than its factorization.

1298521728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 879 (or 864 counting only the distinct ones).

The product of its digits is 161280, while the sum is 45.

The square root of 1298521728 is about 36035.0069793250. The cubic root of 1298521728 is about 1090.9790401208.

The spelling of 1298521728 in words is "one billion, two hundred ninety-eight million, five hundred twenty-one thousand, seven hundred twenty-eight".