1021001728 has 60 divisors (see below), whose sum is σ = 2065500612. Its totient is φ = 504627200.

The previous prime is 1021001693. The next prime is 1021001731. The reversal of 1021001728 is 8271001201.

It can be written as a sum of positive squares in 2 ways, for example, as 496041984 + 524959744 = 22272^2 + 22912^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1021001699 and 1021001708.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1654476 + ... + 1655092.

Almost surely, 2^1021001728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1021001728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1032750306).

1021001728 is an abundant number, since it is smaller than the sum of its proper divisors (1044498884).

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

1021001728 is an frugal number, since it uses more digits than its factorization.

1021001728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746 (or 720 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 1021001728 is about 31953.1176569674. The cubic root of 1021001728 is about 1006.9521318588.

Adding to 1021001728 its reverse (8271001201), we get a palindrome (9292002929).

The spelling of 1021001728 in words is "one billion, twenty-one million, one thousand, seven hundred twenty-eight".