1021551127728 has 20 divisors (see below), whose sum is σ = 2639007080088. Its totient is φ = 340517042560.

The previous prime is 1021551127721. The next prime is 1021551127757. The reversal of 1021551127728 is 8277211551201.

1021551127728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 1021551127728.

It is not an unprimeable number, because it can be changed into a prime (1021551127721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10641157533 + ... + 10641157628.

Almost surely, 2^{1021551127728} is an apocalyptic number.

It is an amenable number.

1021551127728 is an abundant number, since it is smaller than the sum of its proper divisors (1617455952360).

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

1021551127728 is a wasteful number, since it uses less digits than its factorization.

1021551127728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21282315172 (or 21282315166 counting only the distinct ones).

The product of its (nonzero) digits is 78400, while the sum is 42.

Adding to 1021551127728 its reverse (8277211551201), we get a palindrome (9298762678929).

The spelling of 1021551127728 in words is "one trillion, twenty-one billion, five hundred fifty-one million, one hundred twenty-seven thousand, seven hundred twenty-eight".