19640128 has 14 divisors (see below), whose sum is σ = 38973506. Its totient is φ = 9820032.

The previous prime is 19640123. The next prime is 19640209. The reversal of 19640128 is 82104691.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19289664 + 350464 = 4392^2 + 592^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 19640128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19640123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 153375 + ... + 153502.

Almost surely, 2^19640128 is an apocalyptic number.

It is an amenable number.

19640128 is a deficient number, since it is larger than the sum of its proper divisors (19333378).

19640128 is an equidigital number, since it uses as much as digits as its factorization.

19640128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306889 (or 306879 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 19640128 is about 4431.7184026064. The cubic root of 19640128 is about 269.8038264081.

The spelling of 19640128 in words is "nineteen million, six hundred forty thousand, one hundred twenty-eight".