128669761 has 4 divisors (see below), whose sum is σ = 140367024. Its totient is φ = 116972500.

The previous prime is 128669731. The next prime is 128669771. The reversal of 128669761 is 167966821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128669761 - 2¹³ = 128661569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128669701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5848615 + ... + 5848636.

It is an arithmetic number, because the mean of its divisors is an integer number (35091756).

Almost surely, 2^128669761 is an apocalyptic number.

128669761 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

128669761 is a deficient number, since it is larger than the sum of its proper divisors (11697263).

128669761 is a wasteful number, since it uses less digits than its factorization.

128669761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11697262.

The product of its digits is 217728, while the sum is 46.

The square root of 128669761 is about 11343.2694140622. The cubic root of 128669761 is about 504.8458974951.

The spelling of 128669761 in words is "one hundred twenty-eight million, six hundred sixty-nine thousand, seven hundred sixty-one".