128425561 has 4 divisors (see below), whose sum is σ = 140100624. Its totient is φ = 116750500.

The previous prime is 128425559. The next prime is 128425597. The reversal of 128425561 is 165524821.

It is a happy number.

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 128425561 - 2¹ = 128425559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128425061) 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 in 3 ways as a sum of consecutive naturals, for example, 5837515 + ... + 5837536.

It is an arithmetic number, because the mean of its divisors is an integer number (35025156).

Almost surely, 2^128425561 is an apocalyptic number.

128425561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

128425561 is a deficient number, since it is larger than the sum of its proper divisors (11675063).

128425561 is a wasteful number, since it uses less digits than its factorization.

128425561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11675062.

The product of its digits is 19200, while the sum is 34.

The square root of 128425561 is about 11332.5002095742. The cubic root of 128425561 is about 504.5263159504.

The spelling of 128425561 in words is "one hundred twenty-eight million, four hundred twenty-five thousand, five hundred sixty-one".