128459981 has 16 divisors (see below), whose sum is σ = 140652288. Its totient is φ = 116616000.

The previous prime is 128459951. The next prime is 128459987. The reversal of 128459981 is 189954821.

It is a cyclic number.

It is not a de Polignac number, because 128459981 - 2⁶ = 128459917 is a prime.

It is a super-2 number, since 2×128459981² = 33003933437040722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128459987) 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 15 ways as a sum of consecutive naturals, for example, 297836 + ... + 298266.

It is an arithmetic number, because the mean of its divisors is an integer number (8790768).

Almost surely, 2^128459981 is an apocalyptic number.

It is an amenable number.

128459981 is a deficient number, since it is larger than the sum of its proper divisors (12192307).

128459981 is a wasteful number, since it uses less digits than its factorization.

128459981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772.

The product of its digits is 207360, while the sum is 47.

The square root of 128459981 is about 11334.0187488816. The cubic root of 128459981 is about 504.5713854949.

The spelling of 128459981 in words is "one hundred twenty-eight million, four hundred fifty-nine thousand, nine hundred eighty-one".