128942969 has 2 divisors, whose sum is σ = 128942970. Its totient is φ = 128942968.

The previous prime is 128942951. The next prime is 128942999. The reversal of 128942969 is 969249821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71182969 + 57760000 = 8437^2 + 7600^2 .

It is a cyclic number.

It is not a de Polignac number, because 128942969 - 2¹⁶ = 128877433 is a prime.

It is a super-2 number, since 2×128942969² = 33252578509069922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (128942999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64471484 + 64471485.

It is an arithmetic number, because the mean of its divisors is an integer number (64471485).

Almost surely, 2^128942969 is an apocalyptic number.

It is an amenable number.

128942969 is a deficient number, since it is larger than the sum of its proper divisors (1).

128942969 is an equidigital number, since it uses as much as digits as its factorization.

128942969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 50.

The square root of 128942969 is about 11355.3057642672. The cubic root of 128942969 is about 505.2029625632.

The spelling of 128942969 in words is "one hundred twenty-eight million, nine hundred forty-two thousand, nine hundred sixty-nine".