128551965 has 16 divisors (see below), whose sum is σ = 205849728. Its totient is φ = 68505536.

The previous prime is 128551963. The next prime is 128551981. The reversal of 128551965 is 569155821.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 128551965 - 2¹ = 128551963 is a prime.

It is a super-2 number, since 2×128551965² = 33051215410722450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128551963) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21439 + ... + 26771.

It is an arithmetic number, because the mean of its divisors is an integer number (12865608).

Almost surely, 2^128551965 is an apocalyptic number.

128551965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

128551965 is a deficient number, since it is larger than the sum of its proper divisors (77297763).

128551965 is a wasteful number, since it uses less digits than its factorization.

128551965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6948.

The product of its digits is 108000, while the sum is 42.

The square root of 128551965 is about 11338.0758949656. The cubic root of 128551965 is about 504.6917898430.

The spelling of 128551965 in words is "one hundred twenty-eight million, five hundred fifty-one thousand, nine hundred sixty-five".