1428728728581 has 24 divisors (see below), whose sum is σ = 2572948707264. Its totient is φ = 742196741760.

The previous prime is 1428728728573. The next prime is 1428728728591. The reversal of 1428728728581 is 1858278278241.

It is a happy number.

1428728728581 is a `hidden beast` number, since 1 + 4 + 2 + 8 + 7 + 28 + 7 + 28 + 581 = 666.

It is not a de Polignac number, because 1428728728581 - 2³ = 1428728728573 is a prime.

It is a super-2 number, since 2×1428728728581² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1428728728591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1030828116 + ... + 1030829501.

It is an arithmetic number, because the mean of its divisors is an integer number (107206196136).

Almost surely, 2^{1428728728581} is an apocalyptic number.

1428728728581 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1428728728581 is a deficient number, since it is larger than the sum of its proper divisors (1144219978683).

1428728728581 is a wasteful number, since it uses less digits than its factorization.

1428728728581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2061657641 (or 2061657638 counting only the distinct ones).

The product of its digits is 32112640, while the sum is 63.

The spelling of 1428728728581 in words is "one trillion, four hundred twenty-eight billion, seven hundred twenty-eight million, seven hundred twenty-eight thousand, five hundred eighty-one".