128421967 has 2 divisors, whose sum is σ = 128421968. Its totient is φ = 128421966.

The previous prime is 128421959. The next prime is 128421971. The reversal of 128421967 is 769124821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128421967 - 2³ = 128421959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128421977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64210983 + 64210984.

It is an arithmetic number, because the mean of its divisors is an integer number (64210984).

Almost surely, 2^128421967 is an apocalyptic number.

128421967 is a deficient number, since it is larger than the sum of its proper divisors (1).

128421967 is an equidigital number, since it uses as much as digits as its factorization.

128421967 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 40.

The square root of 128421967 is about 11332.3416379846. The cubic root of 128421967 is about 504.5216095029.

The spelling of 128421967 in words is "one hundred twenty-eight million, four hundred twenty-one thousand, nine hundred sixty-seven".