128939221736 has 64 divisors (see below), whose sum is σ = 266596989120. Its totient is φ = 58086282240.

The previous prime is 128939221729. The next prime is 128939221777. The reversal of 128939221736 is 637122939821.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7016336 + ... + 7034688.

It is an arithmetic number, because the mean of its divisors is an integer number (4165577955).

Almost surely, 2^128939221736 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 128939221736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133298494560).

128939221736 is an abundant number, since it is smaller than the sum of its proper divisors (137657767384).

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

128939221736 is a wasteful number, since it uses less digits than its factorization.

128939221736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19986 (or 19982 counting only the distinct ones).

The product of its digits is 1959552, while the sum is 53.

The spelling of 128939221736 in words is "one hundred twenty-eight billion, nine hundred thirty-nine million, two hundred twenty-one thousand, seven hundred thirty-six".