20128916 has 12 divisors (see below), whose sum is σ = 35538132. Its totient is φ = 9975168.

The previous prime is 20128903. The next prime is 20128937. The reversal of 20128916 is 61982102.

It can be written as a sum of positive squares in 2 ways, for example, as 4605316 + 15523600 = 2146^2 + 3940^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21815 + ... + 22718.

It is an arithmetic number, because the mean of its divisors is an integer number (2961511).

Almost surely, 2^20128916 is an apocalyptic number.

It is an amenable number.

20128916 is a deficient number, since it is larger than the sum of its proper divisors (15409216).

20128916 is a wasteful number, since it uses less digits than its factorization.

20128916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44650 (or 44648 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 20128916 is about 4486.5260502977. The cubic root of 20128916 is about 272.0237327908.

The spelling of 20128916 in words is "twenty million, one hundred twenty-eight thousand, nine hundred sixteen".