128691443 has 2 divisors, whose sum is σ = 128691444. Its totient is φ = 128691442.

The previous prime is 128691401. The next prime is 128691461. The reversal of 128691443 is 344196821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128691443 - 2¹⁶ = 128625907 is a prime.

It is a super-2 number, since 2×128691443² = 33122975002844498, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 128691397 and 128691406.

It is not a weakly prime, because it can be changed into another prime (128693443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64345721 + 64345722.

It is an arithmetic number, because the mean of its divisors is an integer number (64345722).

Almost surely, 2^128691443 is an apocalyptic number.

128691443 is a deficient number, since it is larger than the sum of its proper divisors (1).

128691443 is an equidigital number, since it uses as much as digits as its factorization.

128691443 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 38.

The square root of 128691443 is about 11344.2250947343. The cubic root of 128691443 is about 504.8742529116.

It can be divided in two parts, 1286 and 91443, that added together give a palindrome (92729).

The spelling of 128691443 in words is "one hundred twenty-eight million, six hundred ninety-one thousand, four hundred forty-three".