128649616 has 10 divisors (see below), whose sum is σ = 249258662. Its totient is φ = 64324800.

The previous prime is 128649611. The next prime is 128649641. The reversal of 128649616 is 616946821.

It can be written as a sum of positive squares in only one way, i.e., 99920016 + 28729600 = 9996^2 + 5360^2 .

It is not an unprimeable number, because it can be changed into a prime (128649611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4020285 + ... + 4020316.

Almost surely, 2^128649616 is an apocalyptic number.

128649616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

128649616 is a deficient number, since it is larger than the sum of its proper divisors (120609046).

128649616 is an equidigital number, since it uses as much as digits as its factorization.

128649616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8040609 (or 8040603 counting only the distinct ones).

The product of its digits is 124416, while the sum is 43.

The square root of 128649616 is about 11342.3814077997. The cubic root of 128649616 is about 504.8195492909.

The spelling of 128649616 in words is "one hundred twenty-eight million, six hundred forty-nine thousand, six hundred sixteen".