128651947 has 2 divisors, whose sum is σ = 128651948. Its totient is φ = 128651946.

The previous prime is 128651921. The next prime is 128651951. The reversal of 128651947 is 749156821.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128651947 is a prime.

It is not a weakly prime, because it can be changed into another prime (128651977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64325973 + 64325974.

It is an arithmetic number, because the mean of its divisors is an integer number (64325974).

Almost surely, 2^128651947 is an apocalyptic number.

128651947 is a deficient number, since it is larger than the sum of its proper divisors (1).

128651947 is an equidigital number, since it uses as much as digits as its factorization.

128651947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 43.

The square root of 128651947 is about 11342.4841635331. The cubic root of 128651947 is about 504.8225982112.

The spelling of 128651947 in words is "one hundred twenty-eight million, six hundred fifty-one thousand, nine hundred forty-seven".