1028395308721 has 16 divisors (see below), whose sum is σ = 1126926460800. Its totient is φ = 930712970880.

The previous prime is 1028395308709. The next prime is 1028395308757. The reversal of 1028395308721 is 1278035938201.

It is not a de Polignac number, because 1028395308721 - 2³⁷ = 890956355249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1028395308761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2151580 + ... + 2585746.

It is an arithmetic number, because the mean of its divisors is an integer number (70432903800).

Almost surely, 2^{1028395308721} is an apocalyptic number.

1028395308721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1028395308721 is a deficient number, since it is larger than the sum of its proper divisors (98531152079).

1028395308721 is a wasteful number, since it uses less digits than its factorization.

1028395308721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435144.

The product of its (nonzero) digits is 725760, while the sum is 49.

The spelling of 1028395308721 in words is "one trillion, twenty-eight billion, three hundred ninety-five million, three hundred eight thousand, seven hundred twenty-one".