128626647 has 4 divisors (see below), whose sum is σ = 171502200. Its totient is φ = 85751096.

The previous prime is 128626643. The next prime is 128626661. The reversal of 128626647 is 746626821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128626647 - 2² = 128626643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128626599 and 128626608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128626643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21437772 + ... + 21437777.

It is an arithmetic number, because the mean of its divisors is an integer number (42875550).

Almost surely, 2^128626647 is an apocalyptic number.

128626647 is a deficient number, since it is larger than the sum of its proper divisors (42875553).

128626647 is an equidigital number, since it uses as much as digits as its factorization.

128626647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42875552.

The product of its digits is 193536, while the sum is 42.

The square root of 128626647 is about 11341.3688327291. The cubic root of 128626647 is about 504.7895041427.

The spelling of 128626647 in words is "one hundred twenty-eight million, six hundred twenty-six thousand, six hundred forty-seven".