128851969 has 2 divisors, whose sum is σ = 128851970. Its totient is φ = 128851968.

The previous prime is 128851967. The next prime is 128851997. The reversal of 128851969 is 969158821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 110250000 + 18601969 = 10500^2 + 4313^2 .

It is a cyclic number.

It is not a de Polignac number, because 128851969 - 2¹ = 128851967 is a prime.

It is a super-2 number, since 2×128851969² = 33205659830353922, which contains 22 as substring.

Together with 128851967, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (128851963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64425984 + 64425985.

It is an arithmetic number, because the mean of its divisors is an integer number (64425985).

Almost surely, 2^128851969 is an apocalyptic number.

It is an amenable number.

128851969 is a deficient number, since it is larger than the sum of its proper divisors (1).

128851969 is an equidigital number, since it uses as much as digits as its factorization.

128851969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 311040, while the sum is 49.

The square root of 128851969 is about 11351.2981195985. The cubic root of 128851969 is about 505.0840875565.

The spelling of 128851969 in words is "one hundred twenty-eight million, eight hundred fifty-one thousand, nine hundred sixty-nine".