21228077677128 has 32 divisors (see below), whose sum is σ = 60651650506560. Its totient is φ = 6065165050560.

The previous prime is 21228077677039. The next prime is 21228077677159. The reversal of 21228077677128 is 82177677082212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63178802443 + ... + 63178802778.

It is an arithmetic number, because the mean of its divisors is an integer number (1895364078330).

Almost surely, 2^{21228077677128} is an apocalyptic number.

21228077677128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21228077677128 is an abundant number, since it is smaller than the sum of its proper divisors (39423572829432).

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

21228077677128 is a wasteful number, since it uses less digits than its factorization.

21228077677128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126357605237 (or 126357605233 counting only the distinct ones).

The product of its (nonzero) digits is 14751744, while the sum is 60.

The spelling of 21228077677128 in words is "twenty-one trillion, two hundred twenty-eight billion, seventy-seven million, six hundred seventy-seven thousand, one hundred twenty-eight".