109212109128 has 24 divisors (see below), whose sum is σ = 295782795750. Its totient is φ = 36404036352.

The previous prime is 109212109073. The next prime is 109212109129. The reversal of 109212109128 is 821901212901.

It can be written as a sum of positive squares in only one way, i.e., 57591360324 + 51620748804 = 239982^2 + 227202^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 109212109092 and 109212109101.

It is not an unprimeable number, because it can be changed into a prime (109212109129) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 758417353 + ... + 758417496.

Almost surely, 2^109212109128 is an apocalyptic number.

109212109128 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

109212109128 is an abundant number, since it is smaller than the sum of its proper divisors (186570686622).

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

109212109128 is a wasteful number, since it uses less digits than its factorization.

109212109128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1516834861 (or 1516834854 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The spelling of 109212109128 in words is "one hundred nine billion, two hundred twelve million, one hundred nine thousand, one hundred twenty-eight".